[每日 LeetCode] 867. Transpose Matrix

Description:

Given a matrix A, return the transpose of A.

The transpose of a matrix is the matrix flipped over it's main diagonal, switching the row and column indices of the matrix.

Example 1:

Input: [[1,2,3],[4,5,6],[7,8,9]]
Output: [[1,4,7],[2,5,8],[3,6,9]]

Example 2:

Input: [[1,2,3],[4,5,6]]
Output: [[1,4],[2,5],[3,6]]

Note:

1. 1 <= A.length <= 1000
2. 1 <= A[0].length <= 1000

思路：本题要求数组的转置。问题不大，主要注意 C++ 中二维数组的初始化操作

vector<vector<int>> ret(column, vector<int>(row,0));

C++ 代码

class Solution {
public:
    vector<vector<int>> transpose(vector<vector<int>>& A) {
        int column = A[0].size(), row = A.size();
        vector<vector<int>> ret(column, vector<int>(row,0));
        for (int i = 0; i < row; i++){
            for (int j = 0; j < column; j++){
                ret[j][i] = A[i][j];
            }
        }
        return ret;
    }
};

运行时间：28ms

运行内存：11.4M