Tasks Details
easy
Find the missing element in a given permutation.
Task Score
50%
Correctness
20%
Performance
80%
An array A consisting of N different integers is given. The array contains integers in the range [1..(N + 1)], which means that exactly one element is missing.
Your goal is to find that missing element.
Write a function:
def solution(A)
that, given an array A, returns the value of the missing element.
For example, given array A such that:
A[0] = 2 A[1] = 3 A[2] = 1 A[3] = 5the function should return 4, as it is the missing element.
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [0..100,000];
- the elements of A are all distinct;
- each element of array A is an integer within the range [1..(N + 1)].
Copyright 2009–2024 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used Python
Total time used 3 minutes
Effective time used 3 minutes
Notes
not defined yet
Task timeline
Code: 05:18:53 UTC,
java,
autosave
Code: 05:20:52 UTC,
py,
verify,
result: Failed
Analysis
expand all
Example tests
1.
0.036 s
WRONG ANSWER,
got 0 expected 4
Code: 05:21:06 UTC,
py,
autosave
Code: 05:21:07 UTC,
py,
verify,
result: Failed
Analysis
expand all
Example tests
1.
0.036 s
WRONG ANSWER,
got 0 expected 4
stdout:
{0: 0, 1: 0, 2: 0, 3: 0}
Code: 05:21:23 UTC,
py,
verify,
result: Passed
Analysis
Code: 05:21:29 UTC,
py,
verify,
result: Passed
Analysis
Code: 05:21:31 UTC,
py,
final,
score: 
50
Analysis summary
The following issues have been detected: runtime errors.
For example, for the input [] the solution terminated unexpectedly.
Analysis
expand all
Correctness tests
empty_and_single
empty list and single element
empty list and single element
✘
RUNTIME ERROR
tested program terminated with exit code 1
tested program terminated with exit code 1
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, int expected, <class 'NoneType'> found.
2.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, int expected, <class 'NoneType'> found.
missing_first_or_last
the first or the last element is missing
the first or the last element is missing
✘
RUNTIME ERROR
tested program terminated with exit code 1
tested program terminated with exit code 1
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, int expected, <class 'NoneType'> found.
2.
0.036 s
OK
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, int expected, <class 'NoneType'> found.
2.
0.036 s
OK
1.
0.036 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, int expected, <class 'NoneType'> found.
2.
0.036 s
OK
3.
0.036 s
OK
1.
0.036 s
OK
expand all
Performance tests
1.
0.048 s
OK
1.
0.048 s
OK
large_range
range sequence, length = ~100,000
range sequence, length = ~100,000
✘
RUNTIME ERROR
tested program terminated with exit code 1
tested program terminated with exit code 1
1.
0.156 s
RUNTIME ERROR,
tested program terminated with exit code 1
stderr:
Invalid result type, int expected, <class 'NoneType'> found.
2.
0.092 s
OK
3.
0.092 s
OK
1.
0.168 s
OK
1.
0.108 s
OK