[数据结构与算法]566重塑矩阵

这题思路我也想到了，基本和题解一样，就是有一句二维vector的初始化不会写，找了一下写法

vector<vector<int>>ans(r,vector<int>(c));//这句没写出来，卡半天

核心代码是这句

  ans[i / c][i % c] = mat[i / n][i % n];

完整代码如下

#include<iostream>
#include<vector>
using namespace std;
class Solution {
public:
    vector<vector<int>> matrixReshape(vector<vector<int>>& mat, int r, int c) {
        int m = mat.size();
        int n = mat[0].size();
        if (m * n != r * c)return mat;
        vector<vector<int>>ans(r,vector<int>(c));//这句没写出来，卡半天
        for (int i = 0; i < m * n; i++) {
            ans[i / c][i % c] = mat[i / n][i % n];
        }
        return ans;
    }
};
int main() {
    Solution test;
    vector<vector<int>>mat = { {1,2,3,4} };
    int r = 2;
    int c = 2;
    vector<vector<int>>ans=test.matrixReshape(mat, r, c);
    for (int i = 0; i < ans.size(); i++) {
        for (int j = 0; j < ans[i].size(); j++) {
            cout << ans[i][j];
        }
    }
}