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 1 minutes
Notes
not defined yet
Task timeline
Code: 08:51:18 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) {
// write your code in Java SE 8
int[] matchNum = new int[A.length+2];
for(int i=0; i<A.length; i++){
matchNum[A[i]] = 1;
}
for(int i=1; i<matchNum.length; i++){
if(matchNum[i] == 0) return i;
}
return 0;
}
}
Analysis
Code: 08:51:26 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) {
// write your code in Java SE 8
int[] matchNum = new int[A.length+2];
for(int i=0; i<A.length; i++){
matchNum[A[i]] = 1;
}
for(int i=1; i<matchNum.length; i++){
if(matchNum[i] == 0) return i;
}
return -1;
}
}
Analysis
Code: 08:51:32 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) {
// write your code in Java SE 8
int[] matchNum = new int[A.length+2];
for(int i=0; i<A.length; i++){
matchNum[A[i]] = 1;
}
for(int i=1; i<matchNum.length; i++){
if(matchNum[i] == 0) return i;
}
return -1;
}
}
Analysis
Code: 08:51:37 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) {
// write your code in Java SE 8
int[] matchNum = new int[A.length+2];
for(int i=0; i<A.length; i++){
matchNum[A[i]] = 1;
}
for(int i=1; i<matchNum.length; i++){
if(matchNum[i] == 0) return i;
}
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.
0.008 s
OK
2.
0.008 s
OK
1.
0.008 s
OK
2.
0.004 s
OK
1.
0.004 s
OK
2.
0.008 s
OK
1.
0.004 s
OK
2.
0.004 s
OK
3.
0.008 s
OK
1.
0.004 s
OK
expand all
Performance tests
1.
0.024 s
OK
1.
0.028 s
OK
1.
0.244 s
OK
2.
0.120 s
OK
3.
0.124 s
OK
1.
0.248 s
OK
1.
0.144 s
OK