Tasks Details
easy
1.
MaxSliceSum
Find a maximum sum of a compact subsequence of array elements.
Task Score
100%
Correctness
100%
Performance
100%
Task description
A non-empty array A consisting of N integers is given. A pair of integers (P, Q), such that 0 ≤ P ≤ Q < N, is called a slice of array A. The sum of a slice (P, Q) is the total of A[P] + A[P+1] + ... + A[Q].
Write a function:
def solution(A)
that, given an array A consisting of N integers, returns the maximum sum of any slice of A.
For example, given array A such that:
A[0] = 3 A[1] = 2 A[2] = -6 A[3] = 4 A[4] = 0the function should return 5 because:
- (3, 4) is a slice of A that has sum 4,
- (2, 2) is a slice of A that has sum −6,
- (0, 1) is a slice of A that has sum 5,
- no other slice of A has sum greater than (0, 1).
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [1..1,000,000];
- each element of array A is an integer within the range [−1,000,000..1,000,000];
- the result will be an integer within the range [−2,147,483,648..2,147,483,647].
Copyright 2009–2025 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used Python
Time spent on task 1 minutes
Notes
not defined yet
Code: 14:13:13 UTC,
java,
autosave
Code: 14:13:23 UTC,
py,
verify,
result: Passed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
# -*- coding:utf-8 -*-
# &Author AnFany
# Lesson 9:Maximum slice problem
# P 9.1 MaxSliceSum
def solution(A):
"""
返回序列A的子序列和的最大值
:param A: 整数序列
:return: 子序列和的最大值
"""
if len(A) == 1:
return A[0]
else:
max_num = max(A) # 如果数组A中没有正数
if max_num <= 0:
return max_num
else:
sum_num = [] # 存储和值
alive_sum = 0
for i in A:
if i < 0:
sum_num.append(alive_sum)
alive_sum += i
if alive_sum < 0:
sum_num.append(alive_sum - i)
alive_sum = 0
sum_num.append(alive_sum)
return max(sum_num)
Analysis
Code: 14:13:26 UTC,
py,
final,
score:
100
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
# -*- coding:utf-8 -*-
# &Author AnFany
# Lesson 9:Maximum slice problem
# P 9.1 MaxSliceSum
def solution(A):
"""
返回序列A的子序列和的最大值
:param A: 整数序列
:return: 子序列和的最大值
"""
if len(A) == 1:
return A[0]
else:
max_num = max(A) # 如果数组A中没有正数
if max_num <= 0:
return max_num
else:
sum_num = [] # 存储和值
alive_sum = 0
for i in A:
if i < 0:
sum_num.append(alive_sum)
alive_sum += i
if alive_sum < 0:
sum_num.append(alive_sum - i)
alive_sum = 0
sum_num.append(alive_sum)
return max(sum_num)
Analysis summary
The solution obtained perfect score.
Analysis
Detected time complexity:
O(N)
expand all
Correctness tests
1.
0.036 s
OK
2.
0.036 s
OK
3.
0.040 s
OK
1.
0.036 s
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2.
0.036 s
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3.
0.036 s
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4.
0.036 s
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5.
0.036 s
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6.
0.036 s
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7.
0.036 s
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8.
0.036 s
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9.
0.036 s
OK
1.
0.036 s
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2.
0.036 s
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3.
0.036 s
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4.
0.036 s
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5.
0.036 s
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6.
0.036 s
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7.
0.036 s
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8.
0.036 s
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9.
0.036 s
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10.
0.036 s
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11.
0.036 s
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12.
0.036 s
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13.
0.036 s
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14.
0.036 s
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15.
0.036 s
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16.
0.036 s
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17.
0.036 s
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18.
0.036 s
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19.
0.036 s
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20.
0.036 s
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21.
0.036 s
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22.
0.036 s
OK
23.
0.040 s
OK
24.
0.036 s
OK
25.
0.036 s
OK
26.
0.036 s
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27.
0.036 s
OK
1.
0.036 s
OK
1.
0.036 s
OK
1.
0.036 s
OK
1.
0.036 s
OK
1.
0.036 s
OK