力扣-448.找到所有数组中消失的数字

Idea

模拟

class Solution {
public:vector<int> findDisappearedNumbers(vector<int>& nums) {int n = nums.size();vector<int> a(n + 1, 0);for(int i : nums) a[i]++;vector<int> ans;for(int i = 1; i <= n; i++) if(!a[i]) ans.emplace_back(i);return ans;}
};