Tasks Details
medium
A matrix of binary values is given. We can flip the values in selected columns. What is the maximum number of rows that we can obtain that contain all the same values?
Task Score
65%
Correctness
100%
Performance
33%
Matrix A, consisting of N rows and M columns, is given, with each cell containing the value 0 or 1. Rows are numbered from 0 to N−1 (from top to bottom). Columns are numbered from 0 to M−1 (from left to right). The values inside the matrix can be changed: you can select as many columns as you want, and in the selected column(s), every value will be flipped (from 0 to 1, or from 1 to 0).
The goal is to obtain the maximum number of rows whose contents are all the same value (that is, we count rows with all 0s and rows with all 1s).
Write a function:
def solution(A)
that, given matrix A, returns the maximum number of rows containing all the same values that can be obtained after flipping the selected columns.
Examples:
1. Given matrix A with N = 3 rows and M = 4 columns:
the function should return 2. After flipping the values in column 1, the two last rows contain all equal values. Row 1 contains all 0s and row 2 contains all 1s.
2. Given matrix A with N = 4 rows and M = 4 columns:
the function should return 4. After flipping the values in two of the columns (columns 0 and 2), all the rows have the same value. Rows number 0 and 2 contain all 1s, and rows number 1 and 3 contain all 0s.
Write an efficient algorithm for the following assumptions:
- N and M are integers within the range [1..100,000];
- N * M is not greater than 100,000.
Copyright 2009–2025 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used Python
Time spent on task 14 minutes
Notes
not defined yet
Code: 15:12:33 UTC,
java,
autosave
Code: 15:12:45 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = 0
idx = 0
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0:
idx = i
break
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:12:56 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
idx = 0
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0:
idx = i
break
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:14:27 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
idx = 0
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0:
idx = i
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:14:37 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
idx = 0
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0:
idx = i
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:14:49 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:15:32 UTC,
py,
verify,
result: Passed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Analysis
Code: 15:16:08 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 :
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:16:18 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount > onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:16:29 UTC,
py,
autosave
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount > onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount < onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:16:41 UTC,
py,
autosave
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount > onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount < onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount > onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:16:51 UTC,
py,
autosave
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount > onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount < onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount == onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:18:47 UTC,
py,
verify,
result: Passed
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount > onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount < onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount == onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Analysis
Code: 15:19:17 UTC,
py,
autosave
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount > onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount < onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount == onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:19:46 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
if zerocount > 0 and onecount > 0 and zerocount == onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:19:56 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if zerocount > 0 and onecount > 0 and zerocount == onecount:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:20:21 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if matrixcount[i] == 0 or matrixcount[i] == len(matrix:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:20:35 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if matrixcount[i] == 0 or matrixcount[i] == len(matrix[0]):
continue
else:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:21:23 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if matrixcount[i][0 == 0 or matrixcount[i] == len(matrix[0]):
continue
else:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:21:34 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if matrixcount[i][0] == 0 or matrixcount[i][1] == len(matrix[0]):
continue
else:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:21:45 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if matrixcount[i][0] == len(matrix[0]) or matrixcount[i][1] == len(matrix[0]):
continue
else:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:22:31 UTC,
py,
verify,
result: Failed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if matrixcount[i][0] == len(matrix[0]) or matrixcount[i][1] == len(matrix[0]):
continue
else:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Analysis
expand all
Example tests
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Traceback (most recent call last):
File "exec.py", line 132, in <module>
main()
File "exec.py", line 94, in main
result = solution( A )
File "/tmp/solution.py", line 17, in solution
if matrixcount[i][0] == len(matrix[0]) or matrixcount[i][1] == len(matrix[0]):
NameError: name 'matrix' is not defined
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Traceback (most recent call last):
File "exec.py", line 132, in <module>
main()
File "exec.py", line 94, in main
result = solution( A )
File "/tmp/solution.py", line 17, in solution
if matrixcount[i][0] == len(matrix[0]) or matrixcount[i][1] == len(matrix[0]):
NameError: name 'matrix' is not defined
Code: 15:22:42 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if matrixcount[i][0] == len(A[0]) or matrixcount[i][1] == len(matrix[0]):
continue
else:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Code: 15:22:45 UTC,
py,
verify,
result: Passed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if matrixcount[i][0] == len(A[0]) or matrixcount[i][1] == len(A[0]):
continue
else:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Analysis
Code: 15:25:46 UTC,
py,
verify,
result: Passed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if matrixcount[i][0] == len(A[0]) or matrixcount[i][1] == len(A[0]):
continue
else:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Analysis
Code: 15:25:50 UTC,
py,
verify,
result: Passed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if matrixcount[i][0] == len(A[0]) or matrixcount[i][1] == len(A[0]):
continue
else:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return count
Analysis
Code: 15:25:52 UTC,
py,
final,
score:
65
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(A):
maxcount = countEqualRows(A)
matrixcount = []
for i in range(len(A)):
zerocount = 0
onecount = 0
for j in range(len(A[0])):
if A[i][j] == 0:
zerocount += 1
else:
onecount += 1
matrixcount.append([zerocount, onecount])
for i in range(len(A)):
if matrixcount[i][0] == len(A[0]) or matrixcount[i][1] == len(A[0]):
continue
else:
matrixcopy = [x for x in A]
flipvals(matrixcopy, i, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
matrixcopy = [x for x in A]
flipvals(matrixcopy, 0, 1)
maxcount = max(maxcount, countEqualRows(matrixcopy))
return maxcount
def flipvals(A, i, val):
for j in range(len(A[0])):
if A[i][j] == val:
for x1 in range(i, len(A)):
A[x1][j] = 1 - A[x1][j]
for x1 in range(0, i):
A[x1][j] = 1 - A[x1][j]
def countEqualRows(matrix):
count = 0
for i in range(len(matrix)):
total = 0
for j in range(len(matrix[0])):
total += matrix[i][j]
if total == 0 or total == len(matrix[0]):
count += 1
return countAnalysis summary
The following issues have been detected: timeout errors.
Analysis
Detected time complexity:
O(N**2*M)
expand all
Correctness tests
1.
0.036 s
OK
2.
0.036 s
OK
3.
0.036 s
OK
1.
0.036 s
OK
2.
0.036 s
OK
3.
0.036 s
OK
1.
0.036 s
OK
2.
0.036 s
OK
3.
0.036 s
OK
4.
0.036 s
OK
1.
0.036 s
OK
2.
0.036 s
OK
3.
0.036 s
OK
4.
0.036 s
OK
1.
0.036 s
OK
2.
0.036 s
OK
3.
0.036 s
OK
1.
0.052 s
OK
2.
0.052 s
OK
3.
0.044 s
OK
4.
0.040 s
OK
1.
0.084 s
OK
2.
0.040 s
OK
3.
0.700 s
OK
expand all
Performance tests
large_diagonal
Each row contains no more than one occurrence of 1, NM <= 100,000.
Each row contains no more than one occurrence of 1, NM <= 100,000.
✘
TIMEOUT ERROR
running time: 4.932 sec., time limit: 0.608 sec.
running time: 4.932 sec., time limit: 0.608 sec.
1.
4.932 s
TIMEOUT ERROR,
running time: 4.932 sec., time limit: 0.608 sec.
2.
5.016 s
TIMEOUT ERROR,
running time: 5.016 sec., time limit: 0.576 sec.
3.
2.052 s
TIMEOUT ERROR,
running time: 2.052 sec., time limit: 0.656 sec.
4.
2.008 s
TIMEOUT ERROR,
running time: 2.008 sec., time limit: 0.656 sec.
5.
0.384 s
OK
1.
6.000 s
TIMEOUT ERROR,
Killed. Hard limit reached: 6.000 sec.
2.
3.652 s
TIMEOUT ERROR,
running time: 3.652 sec., time limit: 0.688 sec.
3.
6.000 s
TIMEOUT ERROR,
Killed. Hard limit reached: 6.000 sec.
1.
0.220 s
OK
1.
0.400 s
OK