Missing Number
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
.
Note:
Your algorithm should run in linear runtime complexity. Could you implement it using only constant extra space complexity?
Solution:
public class Solution {
public int missingNumber(int[] nums) {
int sum = 0, n = nums.length;
for (int i = 0; i < n; i++)
sum += nums[i];
return n * (1 + n) / 2 - sum;
}
}