Today I have done leetcode's February LeetCoding Challenge with cpp.

February LeetCoding Challenge 15

Description

Single Number

Given a non-empty array of integers nums, every element appears twice except for one. Find that single one.

You must implement a solution with a linear runtime complexity and use only constant extra space.

Example 1:

Input: nums = [2,2,1]
Output: 1

Example 2:

Input: nums = [4,1,2,1,2]
Output: 4

Example 3:

Input: nums = [1]
Output: 1

Constraints:

• 1 <= nums.length <= 3 * 10^4
• -3 * 104 <= nums[i] <= 3 * 10^4
• Each element in the array appears twice except for one element which appears only once.

Solution

auto speedup = [](){
  cin.tie(nullptr);
  cout.tie(nullptr);
  ios::sync_with_stdio(false);
  return 0;
}();
class Solution {
public:
  int singleNumber(vector<int>& nums) {
    return accumulate(nums.begin(), nums.end(), 0, [](int a, int b) {
      return a ^ b;
    });
  }
};

// Accepted
// 61/61 cases passed (27 ms)
// Your runtime beats 53.51 % of cpp submissions
// Your memory usage beats 50.83 % of cpp submissions (17 MB)