LeetCode 1329. 将矩阵按对角线排序_leetcode 1329:将矩阵按对角线排序c++

原题目：https://leetcode-cn.com/problems/sort-the-matrix-diagonally/

思路：

用临时数组存储每一个对角线的元素，排序后，赋值给新的矩阵对角线即可

代码：

class Solution {
public:
    vector<vector<int>> diagonalSort(vector<vector<int>>& mat) {
        if(mat.size()==0 || mat[0].size()==0) return mat;
        int n = mat.size(),m = mat[0].size();
        vector<vector<int>> ans(n,vector<int>(m));
 
        for(int i=m-1;i>=0;--i){
            int row=0,col=i,index=-1;
            vector<int> tmp;
            while(row<n&&col<m){
                tmp.push_back(mat[row][col]);
                ++row;++col;
            }
            sort(tmp.begin(),tmp.end());
            row=0,col = i;
            while(row<n&&col<m){
                ans[row][col] = tmp[++index];
                ++row;++col;
            }
        }
        for(int i=1;i<n;++i){
            int row=i,col=0,index=-1;
            vector<int> tmp;
            while(row<n&&col<m){
                tmp.push_back(mat[row][col]);
                ++row;++col;
            }
            sort(tmp.begin(),tmp.end());
            row=i,col = 0;
            while(row<n&&col<m){
                ans[row][col] = tmp[++index];
                ++row;++col;
            }
        }
        return ans;
    }
};