【力扣·每日一题】2022. 将一维数组转变成二维数组（C++ 模拟 vector）

class Solution {
public:
    vector<vector<int>> construct2DArray(vector<int>& original, int m, int n) {
        vector<vector<int>>ans;
        if(n*m!=original.size()) return ans;
        vector<int>tmp;
        for(int i=0;i<original.size();i++){
            tmp.push_back(original[i]);
            if(tmp.size()==n) ans.push_back(tmp),tmp.clear();
        }
        return ans;
    }
};