Codility----PermMissingElem
Task description
A zero-indexed 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 a zero-indexed 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.
Assume that:
- 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)].
Complexity:
- expected worst-case time complexity is O(N);
- expected worst-case space complexity is O(1), beyond input storage (not counting the storage required for input arguments).
Elements of input arrays can be modified.
Solution
Programming language used: Java
Total time used: 4 minutes
Code: 10:43:42 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) {
// write your code in Java SE 8
int res = 0;
int max = A.length;
if(max==0)
return 1;
Arrays.sort(A);
for(int i=0; i<max; i++){
res = (i+1)^A[i];
if(res != 0)
return (i+1);
}
return max+1;
}
}