LeetCode 448. 找到所有数组中消失的数字(哈希表)

class Solution {
public:
    vector<int> findDisappearedNumbers(vector<int>& nums) {
        vector<int> result;
        map<int, int> mp;
        for (int i = 1; i <= nums.size(); i++) {
            mp[i] = 0;
        }
        for (int i = 0; i < nums.size(); i++) {
            mp[nums[i]]++;
        }
        for (int i = 1; i <= nums.size(); i++) {
            if (mp[i] == 0) result.push_back(i);
        }
        return result;
    }
};