Tasks Details
easy
1.
Distinct
Compute number of distinct values in an array.
Task Score
100%
Correctness
100%
Performance
100%
Write a function
function solution($A);
that, given an array A consisting of N integers, returns the number of distinct values in array A.
For example, given array A consisting of six elements such that:
A[0] = 2 A[1] = 1 A[2] = 1 A[3] = 2 A[4] = 3 A[5] = 1the function should return 3, because there are 3 distinct values appearing in array A, namely 1, 2 and 3.
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [0..100,000];
- each element of array A is an integer within the range [−1,000,000..1,000,000].
Copyright 2009–2025 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used PHP
Time spent on task 1 minutes
Notes
not defined yet
Analysis
Compile error
func.c: In function 'solution':
func.c:5:5: warning: implicit declaration of function 'count' [-Wimplicit-function-declaration]
count(array_flip(array_flip(array_reverse($A, true))));
^
func.c:5:5: warning: implicit declaration of function 'array_flip' [-Wimplicit-function-declaration]
func.c:5:5: warning: implicit declaration of function 'array_reverse' [-Wimplicit-function-declaration]
func.c:5:47: error: '$A' undeclared (first use in this function)
count(array_flip(array_flip(array_reverse($A, true))));
^
func.c:5:47: note: each undeclared identifier is reported only once for each function it appears in
func.c:5:51: error: 'true' undeclared (first use in this function)
count(array_flip(array_flip(array_reverse($A, true))));
^
func.c:6:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
Analysis
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Example tests
1.
0.026 s
RUNTIME ERROR,
tested program terminated unexpectedly
stderr:
Invalid result type, int expected.
Analysis
Analysis
Analysis summary
The solution obtained perfect score.
Analysis
Detected time complexity:
O(N*log(N)) or O(N)
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Correctness tests
1.
0.025 s
OK
1.
0.025 s
OK
2.
0.025 s
OK
1.
0.025 s
OK
1.
0.025 s
OK
1.
0.024 s
OK
1.
0.025 s
OK
1.
0.026 s
OK
1.
0.026 s
OK
1.
0.026 s
OK