# LeetCode – Missing Number (Java)

Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array. For example, given nums = [0, 1, 3] return 2.

Java Solution 1 - Math

```public int missingNumber(int[] nums) { int sum=0; for(int i=0; i<nums.length; i++){ sum+=nums[i]; }   int n=nums.length; return n*(n+1)/2-sum; }```

Java Solution 2 - Bit

```public int missingNumber(int[] nums) {   int miss=0; for(int i=0; i<nums.length; i++){ miss ^= (i+1) ^nums[i]; }   return miss; }```

Java Solution 3 - Binary Search

```public int missingNumber(int[] nums) { Arrays.sort(nums); int l=0, r=nums.length; while(l<r){ int m = (l+r)/2; if(nums[m]>m){ r=m; }else{ l=m+1; } }   return r; }```
Category >> Algorithms
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• Anurag Patel

public class Solution {
public int missingNumber(int[] nums) {
Arrays.sort(nums);
if(nums[0] != 0)
return 0;
int i=1;
for(i=1;i<nums.length;i++){
if(nums[i] – nums[i-1] != 1)
return i;
}
return i;
}
}