missing-number

Missing number

Problem link

Solutions

Solution.cpp

// https://leetcode.com/problems/missing-number

class Solution {
 public:
  int missingNumber(vector<int>& nums) {
    int ret = 0;
    for (int x : nums) ret ^= x;
    for (int i = 1, n = nums.size(); i <= n; ++i) ret ^= i;
    return ret;
  }
};

Tags

• Bitwise operation
• Unique/duplicate element finding with bizarro algorithms