用STL编写矩阵就地转置

可以使用STL中的vector来表示矩阵，然后再对其进行就地转置。以下是示例代码：

#include <iostream>
#include <vector>

using namespace std;

void transpose(vector<vector<int>>& matrix) {
    int n = matrix.size(), m = matrix[0].size();
    for(int i = 0; i < n; i++) {
        for(int j = i + 1; j < m; j++) {
            swap(matrix[i][j], matrix[j][i]);
        }
    }
}

int main() {
    vector<vector<int>> matrix = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
    cout << "Original matrix:" << endl;
    for(auto row: matrix) {
        for(auto val: row) {
            cout << val << " ";
        }
        cout << endl;
    }
    transpose(matrix);
    cout << "Transposed matrix:" << endl;
    for(auto row: matrix) {
        for(auto val: row) {
            cout << val << " ";
        }
        cout << endl;
    }
    return 0;
}

运行结果：

Original matrix:
1 2 3 
4 5 6 
7 8 9 
Transposed matrix:
1 4 7 
2 5 8 
3 6 9