# 矩陣中第一行和最后一行的交換元素 > 原文： [https://www.geeksforgeeks.org/interchange-elements-of-first-and-last-rows-in-matrix/](https://www.geeksforgeeks.org/interchange-elements-of-first-and-last-rows-in-matrix/) 給定 4 x 4 矩陣，我們必須交換第一行和最后一行的元素，并顯示結果矩陣。 **示例**： ``` Input : 3 4 5 0 2 6 1 2 2 7 1 2 2 1 1 2 Output : 2 1 1 2 2 6 1 2 2 7 1 2 3 4 5 0 Input : 9 7 5 1 2 3 4 1 5 6 6 5 1 2 3 1 Output : 1 2 3 1 2 3 4 1 5 6 6 5 9 7 5 1 ``` 該方法非常簡單，我們可以簡單地交換矩陣第一行和最后一行的元素，以獲取所需的矩陣作為輸出。 下面是該方法的實現： ## C++ ```cpp // C++ code to swap the element of first // and last row and display the result #include <iostream> using namespace std; #define n 4 void interchangeFirstLast(int m[][n]) { ????????int rows = n; ????????// swapping of element between first ????????// and last rows ????????for (int i = 0; i < n; i++) ????????{ ????????????int t = m[0][i]; ????????????m[0][i] = m[rows - 1][i]; ????????????m[rows - 1][i] = t; ????????} }? // Driver function int main() { ????// input in the array ????int m[n][n] = { { 8, 9, 7, 6 }, ????????????????{ 4, 7, 6, 5 }, ????????????????{ 3, 2, 1, 8 }, ????????????????{ 9, 9, 7, 7 } };? ????interchangeFirstLast(m);? ????// printing the interchanged matrix ????for (int i = 0; i < n; i++) ????{ ????????for (int j = 0; j < n; j++)? ????????????cout << m[i][j] << " "; ????????cout << endl; ????} } // This code is contributed by Anant Agarwal. ```