Tasks Details
easy
Find the missing element in a given permutation.
Task Score
100%
Correctness
100%
Performance
100%
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:
class Solution { public int solution(int[] 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 Java 8
Time spent on task 7 minutes
Notes
not defined yet
Task timeline
Code: 05:57:37 UTC,
java,
autosave
Code: 06:02:30 UTC,
java,
autosave
Code: 06:02:54 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");
class Solution {
public int solution(int[] A) {
int difference = A.length + 1;
for (int idx = 0; idx < A.length; idx++) {
}
return difference;
}
}
Code: 06:03:08 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");
class Solution {
public int solution(int[] A) {
int difference = A.length + 1;
for (int idx = 0; idx < A.length; idx++) {
difference += (idx + 1)
}
return difference;
}
}
Code: 06:03:18 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");
class Solution {
public int solution(int[] A) {
int difference = A.length + 1;
for (int idx = 0; idx < A.length; idx++) {
difference += (idx + 1) - A[idx];
}
return difference;
}
}
Code: 06:03:30 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");
class Solution {
public int solution(int[] A) {
int difference = A.length + 1;
for (int idx = 0; idx < A.length; idx++) {
difference += (idx + 1) - A[idx];
}
return difference;
}
}
Analysis
Code: 06:03:37 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");
class Solution {
public int solution(int[] A) {
int difference = A.length + 1;
for (int idx = 0; idx < A.length; idx++) {
difference += (idx + 1) - A[idx];
}
return difference;
}
}
Analysis
Code: 06:03:41 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");
class Solution {
public int solution(int[] A) {
int difference = A.length + 1;
for (int idx = 0; idx < A.length; idx++) {
difference += (idx + 1) - A[idx];
}
return difference;
}
}
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.
0.008 s
OK
1.
0.008 s
OK
2.
0.008 s
OK
1.
0.012 s
OK
2.
0.008 s
OK
3.
0.008 s
OK
1.
0.008 s
OK
expand all
Performance tests
1.
0.032 s
OK
1.
0.028 s
OK
1.
0.244 s
OK
2.
0.128 s
OK
3.
0.128 s
OK
1.
0.248 s
OK
1.
0.152 s
OK