Tasks Details
medium
Find the minimal nucleotide from a range of sequence DNA.
Task Score
62%
Correctness
100%
Performance
0%
A DNA sequence can be represented as a string consisting of the letters A, C, G and T, which correspond to the types of successive nucleotides in the sequence. Each nucleotide has an impact factor, which is an integer. Nucleotides of types A, C, G and T have impact factors of 1, 2, 3 and 4, respectively. You are going to answer several queries of the form: What is the minimal impact factor of nucleotides contained in a particular part of the given DNA sequence?
The DNA sequence is given as a non-empty string S = S[0]S[1]...S[N-1] consisting of N characters. There are M queries, which are given in non-empty arrays P and Q, each consisting of M integers. The K-th query (0 ≤ K < M) requires you to find the minimal impact factor of nucleotides contained in the DNA sequence between positions P[K] and Q[K] (inclusive).
For example, consider string S = CAGCCTA and arrays P, Q such that:
P[0] = 2 Q[0] = 4 P[1] = 5 Q[1] = 5 P[2] = 0 Q[2] = 6The answers to these M = 3 queries are as follows:
- The part of the DNA between positions 2 and 4 contains nucleotides G and C (twice), whose impact factors are 3 and 2 respectively, so the answer is 2.
- The part between positions 5 and 5 contains a single nucleotide T, whose impact factor is 4, so the answer is 4.
- The part between positions 0 and 6 (the whole string) contains all nucleotides, in particular nucleotide A whose impact factor is 1, so the answer is 1.
Write a function:
def solution(S, P, Q)
that, given a non-empty string S consisting of N characters and two non-empty arrays P and Q consisting of M integers, returns an array consisting of M integers specifying the consecutive answers to all queries.
Result array should be returned as an array of integers.
For example, given the string S = CAGCCTA and arrays P, Q such that:
P[0] = 2 Q[0] = 4 P[1] = 5 Q[1] = 5 P[2] = 0 Q[2] = 6the function should return the values [2, 4, 1], as explained above.
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [1..100,000];
- M is an integer within the range [1..50,000];
- each element of arrays P and Q is an integer within the range [0..N - 1];
- P[K] ≤ Q[K], where 0 ≤ K < M;
- string S consists only of upper-case English letters A, C, G, T.
Copyright 2009–2025 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used Python
Time spent on task 33 minutes
Notes
not defined yet
Task timeline
Code: 05:32:33 UTC,
java,
autosave
Code: 05:52:31 UTC,
py,
autosave
Code: 05:53:56 UTC,
py,
verify,
result: Failed
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 155, in <module>
main()
File "exec.py", line 117, in main
result = solution( S, P, Q )
File "/tmp/solution.py", line 7, in solution
for i, p , q in enumerate(zip(P, Q)):
ValueError: not enough values to unpack (expected 3, got 2)
Code: 05:54:13 UTC,
py,
verify,
result: Failed
Analysis
expand all
Example tests
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, array expected, <class 'NoneType'> found.stdout:
0 2 4 1 5 5 2 0 6
Code: 05:55:25 UTC,
py,
verify,
result: Failed
Analysis
expand all
Example tests
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, array expected, <class 'NoneType'> found.stdout:
GC CAGCCT
Code: 05:56:00 UTC,
py,
verify,
result: Failed
Analysis
expand all
Example tests
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, array expected, <class 'NoneType'> found.stdout:
0 2 4 1 5 5 2 0 6
Code: 05:56:14 UTC,
py,
verify,
result: Failed
Analysis
expand all
Example tests
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, array expected, <class 'NoneType'> found.stdout:
0 2 4 GC 1 5 5 2 0 6 CAGCCT
Code: 05:56:41 UTC,
py,
verify,
result: Failed
Analysis
expand all
Example tests
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, array expected, <class 'NoneType'> found.stdout:
0 2 4 GCC 1 5 5 T 2 0 6 CAGCCTA
Code: 05:59:18 UTC,
py,
autosave
Code: 05:59:42 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
#print(i, p, q)
#print(S[p:q + 1])
Code: 05:59:53 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
#print(i, p, q)
#print(S[p:q + 1])
Code: 06:00:12 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
#print(i, p, q)
#print(S[p:q + 1])
string_hash[i] = S[p:q+1]
Code: 06:00:21 UTC,
py,
verify,
result: Failed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
#print(i, p, q)
#print(S[p:q + 1])
string_hash[i] = S[p:q+1]
print(string_hash)
Analysis
expand all
Example tests
1.
0.040 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, array expected, <class 'NoneType'> found.stdout:
defaultdict(<class 'str'>, {0: 'GCC', 1: 'T', 2: 'CAGCCTA'})
Code: 06:00:44 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
#print(i, p, q)
#print(S[p:q + 1])
string_hash[i] = soS[p:q+1]
print(string_hash)
Code: 06:00:49 UTC,
py,
verify,
result: Failed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
#print(i, p, q)
#print(S[p:q + 1])
string_hash[i] = sorted(S[p:q+1])
print(string_hash)
Analysis
expand all
Example tests
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, array expected, <class 'NoneType'> found.stdout:
defaultdict(<class 'str'>, {0: ['C', 'C', 'G'], 1: ['T'], 2: ['A', 'A', 'C', 'C', 'C', 'G', 'T']})
Code: 06:01:30 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
string_hash[i] = sorted(S[p:q+1])
print(string_hash)
Code: 06:01:42 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
sorted(S[p:q+1])[0]
print(string_hash)
Code: 06:01:50 UTC,
py,
verify,
result: Failed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
print(sorted(S[p:q+1])[0])
Analysis
expand all
Example tests
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, array expected, <class 'NoneType'> found.stdout:
C T A
Code: 06:02:12 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash_ = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
has
Code: 06:02:29 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
hash_alpha[min_num]
Code: 06:02:49 UTC,
py,
verify,
result: Failed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
answer_list = list()
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
answer_list += hash_alpha[min_num]
print(answer_list)
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 155, in <module>
main()
File "exec.py", line 117, in main
result = solution( S, P, Q )
File "/tmp/solution.py", line 13, in solution
answer_list += hash_alpha[min_num]
TypeError: 'int' object is not iterable
Code: 06:03:07 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
answer_list = list()
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
answer_list += hash_alpha[min_num]
Code: 06:03:17 UTC,
py,
verify,
result: Failed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
answer_list = list()
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
answer_list += hash_alpha[min_num]
print(answer_list)
Analysis
expand all
Example tests
1.
0.040 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Traceback (most recent call last):
File "exec.py", line 155, in <module>
main()
File "exec.py", line 117, in main
result = solution( S, P, Q )
File "/tmp/solution.py", line 13, in solution
answer_list += hash_alpha[min_num]
TypeError: 'int' object is not iterable
Code: 06:03:29 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
answer_list = list()
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
answer_list += hash_alpha[min_num]
Code: 06:03:46 UTC,
py,
verify,
result: Failed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
answer_list = list()
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
print(hash_alpha[min_num])
Analysis
expand all
Example tests
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, array expected, <class 'NoneType'> found.stdout:
2 4 1
Code: 06:03:59 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
answer_list = list()
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
answer_list.append(hash_alpha[min_num])
prin
Code: 06:04:04 UTC,
py,
verify,
result: Failed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
import collections
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
answer_list = list()
string_hash = collections.defaultdict(str)
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
answer_list.append(hash_alpha[min_num])
print(answer_list)
Analysis
expand all
Example tests
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, array expected, <class 'NoneType'> found.stdout:
[2, 4, 1]
Code: 06:04:20 UTC,
py,
autosave
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
answer_list = list()
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
answer_list.append(hash_alpha[min_num])
return answer_list
Code: 06:04:21 UTC,
py,
verify,
result: Passed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
answer_list = list()
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
answer_list.append(hash_alpha[min_num])
return answer_list
Analysis
Code: 06:04:26 UTC,
py,
verify,
result: Passed
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
answer_list = list()
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
answer_list.append(hash_alpha[min_num])
return answer_list
Analysis
Code: 06:04:28 UTC,
py,
final,
score:
62
# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")
def solution(S, P, Q):
hash_alpha = {'A' : 1, 'C' : 2, 'G' : 3, 'T': 4 }
answer_list = list()
for i, (p , q) in enumerate(zip(P, Q)):
min_num = sorted(S[p:q+1])[0]
answer_list.append(hash_alpha[min_num])
return answer_listAnalysis summary
The following issues have been detected: timeout errors.
Analysis
Detected time complexity:
O(N * M)
expand all
Correctness tests
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.
0.040 s
OK
1.
0.036 s
OK
1.
0.036 s
OK
expand all
Performance tests
almost_all_same_letters
GGGGGG..??..GGGGGG..??..GGGGGG
GGGGGG..??..GGGGGG..??..GGGGGG
✘
TIMEOUT ERROR
Killed. Hard limit reached: 6.000 sec.
Killed. Hard limit reached: 6.000 sec.
1.
6.000 s
TIMEOUT ERROR,
Killed. Hard limit reached: 6.000 sec.
2.
0.040 s
OK
1.
6.000 s
TIMEOUT ERROR,
Killed. Hard limit reached: 6.000 sec.
1.
7.000 s
TIMEOUT ERROR,
Killed. Hard limit reached: 7.000 sec.