Leetcode 448 Find All Numbers Disappeared in an Array

Leetcode 448 Find All Numbers Disappeared in an Array

#include <vector>using namespace std;class Solution {public:    vector<int> findDisappearedNumbers(vector<int>& nums) {        vector<int> disappear;        vector<int> freq(nums.size());        for (int i = 0; i < nums.size(); i++){            freq[nums[i] - 1] ++;//从1开始        }        for (int i = 0; i < freq.size(); i++){            if (freq[i] == 0)                disappear.push_back(i+1);        }        return disappear;    }};