题目

地址

https://leetcode.com/problems/the-two-sneaky-numbers-of-digitville/description/

内容

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:

Input: nums = [0,1,1,0]
Output: [0,1]
Explanation:
The numbers 0 and 1 each appear twice in the array.

Example 2:

Input: nums = [0,3,2,1,3,2]
Output: [2,3]
Explanation:
The numbers 2 and 3 each appear twice in the array.

Example 3:

Input: nums = [7,1,5,4,3,4,6,0,9,5,8,2]
Output: [4,5]
Explanation:
The numbers 4 and 5 each appear twice in the array.

Constraints:

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

解题

这题就是要在一个数组中找到重复的数。方法就是使用一个set结构来做去重。

#include <set>
#include <vector>
using namespace std;

class Solution {
public:
    vector<int> getSneakyNumbers(vector<int>& nums) {
        set<int> s;
        vector<int> result;
        for (auto num : nums) {
            if (s.find(num) == s.end()) {
                s.insert(num);
            } else {
                result.push_back(num);
            }
        } 
        return result;    
    }
};

代码地址

https://github.com/f304646673/leetcode/tree/main/3289-The-Two-Sneaky-Numbers-of-Digitville/cplusplus