Tasks Details
easy
1.
PermCheck
Check whether array A is a permutation.
Task Score
100%
Correctness
100%
Performance
100%
A non-empty array A consisting of N integers is given.
A permutation is a sequence containing each element from 1 to N once, and only once.
For example, array A such that:
A[0] = 4 A[1] = 1 A[2] = 3 A[3] = 2is a permutation, but array A such that:
A[0] = 4 A[1] = 1 A[2] = 3is not a permutation, because value 2 is missing.
The goal is to check whether array A is a permutation.
Write a function:
class Solution { public int solution(int[] A); }
that, given an array A, returns 1 if array A is a permutation and 0 if it is not.
For example, given array A such that:
A[0] = 4 A[1] = 1 A[2] = 3 A[3] = 2the function should return 1.
Given array A such that:
A[0] = 4 A[1] = 1 A[2] = 3the function should return 0.
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [1..100,000];
- each element of array A is an integer within the range [1..1,000,000,000].
Copyright 2009–2024 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used Java 8
Time spent on task 4 minutes
Notes
not defined yet
Task timeline
Code: 07:50:19 UTC,
java,
autosave
Code: 07:52:31 UTC,
java,
autosave
Code: 07:53:02 UTC,
java,
autosave
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
import java.util.Arrays;
class Solution {
public int solution(int[] A) {
Arrays.sort(A);
for (int idx = 0; idx < A.length; idx++) {
if (A[idx] != idx + 1)
}
}
}
Code: 07:53:10 UTC,
java,
verify,
result: Failed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
import java.util.Arrays;
class Solution {
public int solution(int[] A) {
Arrays.sort(A);
for (int idx = 0; idx < A.length; idx++) {
if (A[idx] != idx + 1) {
return 0
}
}
return 1;
}
}
Analysis
Compile error
Solution.java:14: error: ';' expected
return 0
^
1 error
Code: 07:53:16 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
import java.util.Arrays;
class Solution {
public int solution(int[] A) {
Arrays.sort(A);
for (int idx = 0; idx < A.length; idx++) {
if (A[idx] != idx + 1) {
return 0;
}
}
return 1;
}
}
Analysis
Code: 07:53:21 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
import java.util.Arrays;
class Solution {
public int solution(int[] A) {
Arrays.sort(A);
for (int idx = 0; idx < A.length; idx++) {
if (A[idx] != idx + 1) {
return 0;
}
}
return 1;
}
}
Analysis
Code: 07:53:26 UTC,
java,
final,
score:
100
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
import java.util.Arrays;
class Solution {
public int solution(int[] A) {
Arrays.sort(A);
for (int idx = 0; idx < A.length; idx++) {
if (A[idx] != idx + 1) {
return 0;
}
}
return 1;
}
}
Analysis summary
The solution obtained perfect score.
Analysis
Detected time complexity:
O(N) or O(N * log(N))
expand all
Correctness tests
1.
0.012 s
OK
2.
0.008 s
OK
1.
0.008 s
OK
2.
0.004 s
OK
1.
0.008 s
OK
2.
0.008 s
OK
3.
0.004 s
OK
4.
0.004 s
OK
1.
0.008 s
OK
2.
0.008 s
OK
3.
0.008 s
OK
4.
0.004 s
OK
1.
0.008 s
OK
2.
0.012 s
OK
permutations_of_ranges
permutations of sets like [2..100] for which the anwsers should be false
permutations of sets like [2..100] for which the anwsers should be false
✔
OK
1.
0.004 s
OK
2.
0.004 s
OK
3.
0.004 s
OK
expand all
Performance tests
1.
0.032 s
OK
2.
0.036 s
OK
1.
0.248 s
OK
2.
0.248 s
OK
1.
0.292 s
OK
2.
0.296 s
OK
1.
0.248 s
OK
2.
0.248 s
OK
1.
0.008 s
OK
2.
0.156 s
OK
3.
0.004 s
OK
1.
0.004 s
OK
2.
0.008 s
OK
3.
0.036 s
OK
4.
0.252 s
OK
5.
0.292 s
OK