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

October LeetCoding Challenge 31

Description

The Two Sneaky Numbers of Digitville

In the town of Digitville, there was a list of numbers called nums containing integers from 0 to n - 1. Each number was supposed to appear exactly once in the list, however, two mischievous numbers sneaked in an additional time, making the list longer than usual.

As the town detective, your task is to find these two sneaky numbers. Return an array of size two containing the two numbers (in any order), so peace can return to Digitville.

Example 1:

Example 2:

Example 3:

Constraints:

• 2 <= n <= 100
• nums.length == n + 2
• 0 <= nums[i] < n
• The input is generated such that nums contains exactly two repeated elements.

Solution

class Solution {
public:
  vector<int> getSneakyNumbers(vector<int>& nums) {
    sort(nums.begin(), nums.end());
    int prev = -1;
    vector<int> answer;
    answer.reserve(2);
    for(auto n : nums) {
      if(n == prev) answer.push_back(n);
      prev = n;
    }
    return answer;
  }
};

// Accepted
// 706/706 cases passed (0 ms)
// Your runtime beats 100 % of cpp submissions
// Your memory usage beats 95.85 % of cpp submissions (25.2 MB)