Find missing number

Problem

Given an integer array of size n containing distinct values in the range from 0 to n (inclusive), return the only number missing from the array within this range.

Examples

Input: nums = [0, 2, 3, 1, 4]

Output: 5

Explanation: nums contains 0, 1, 2, 3, 4 thus leaving 5 as the only missing number in the range [0, 5]

Input: nums = [0, 1, 2, 4, 5, 6]

Output: 3

Explanation: nums contains 0, 1, 2, 4, 5, 6 thus leaving 3 as the only missing number in the range [0, 6]

Solution

class Solution {
    public int missingNumber(int[] nums) {
        int n = nums.length;
        int arrSum = 0;
        int sum = (n * (n + 1))/2;

        for(int i :  nums) arrSum += i;

        return sum - arrSum;
    }
}