Missing Number

Missing Number.java

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

public class Solution {
    public int missingNumber(int[] nums) {
        int max = findMax(nums);
        int result = 0;
        for(int i = 0; i < max; i++){
            if(i < nums.length){
                result = result ^ i+1 ^ nums[i];
            }else {result=result ^ i+1;}
        }
        return result;
    }
    
    int findMax(int[] nums){
        int max = nums[0];
        for(int i = 1; i < nums.length; i++){
            if(max < nums[i]){
                max = nums[i];
            }
        }
        return max == nums.length-1 ? ++max: max;
    }    
}