# Program to swap upper diagonal elements with lower diagonal elements of matrix.

Given a square matrix, swap upper diagonal elements of matrix with lower diagonal elements of matrix.

Examples :

```Input:   2  3  5  6
4  5  7  9
8  6  4  9
1  3  5  6

Output:  2  4  8  1
3  5  6  3
5  7  4  5
6  9  9  6

Input:   1  2  3
4  5  6
7  8  9

Output:  1  4  7
2  5  8
3  6  9
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Below is the implementation of above idea :

## C++

 `// CPP Program to implement matrix ` `// for swapping the upper diagonal ` `// elements with lower diagonal  ` `// elements of matrix. ` `#include ` `#define n 4 ` `using` `namespace` `std; ` ` `  `// Function to swap the diagonal  ` `// elements in a matrix. ` `void` `swapUpperToLower(``int` `arr[n][n]) ` `{ ` `    ``// Loop for swap the elements of matrix. ` `    ``for` `(``int` `i = 0; i < n; i++) { ` `        ``for` `(``int` `j = i + 1; j < n; j++) { ` `            ``int` `temp = arr[i][j]; ` `            ``arr[i][j] = arr[j][i]; ` `            ``arr[j][i] = temp; ` `        ``} ` `    ``} ` `     `  `    ``// Loop for print the matrix elements. ` `    ``for` `(``int` `i = 0; i < n; i++) { ` `        ``for` `(``int` `j = 0; j < n; j++) ` `            ``cout << arr[i][j] << ``" "``; ` `        ``cout << endl; ` `    ``} ` `} ` ` `  `// Driver function to run the program ` `int` `main() ` `{ ` `    ``int` `arr[n][n] = { { 2, 3, 5, 6 }, ` `                    ``{ 4, 5, 7, 9 }, ` `                    ``{ 8, 6, 4, 9 }, ` `                    ``{ 1, 3, 5, 6 } }; ` ` `  `    ``// Function call ` `    ``swapUpperToLower(arr); ` `    ``return` `0; ` `} ` ` `  `} `

## Java

 `// java Program to implement matrix ` `// for swapping the upper diagonal ` `// elements with lower diagonal  ` `// elements of matrix. ` `import` `java.io.*; ` ` `  `class` `GFG ` `{ ` `    ``static` `int` `n = ``4``; ` `     `  `    ``// Function to swap the diagonal  ` `    ``// elements in a matrix. ` `    ``static` `void` `swapUpperToLower(``int` `arr[][]) ` `    ``{ ` `        ``// Loop for swap the elements of matrix. ` `        ``for` `(``int` `i = ``0``; i < n; i++)  ` `        ``{ ` `            ``for` `(``int` `j = i + ``1``; j < n; j++)  ` `            ``{ ` `                ``int` `temp = arr[i][j]; ` `                ``arr[i][j] = arr[j][i]; ` `                ``arr[j][i] = temp; ` `            ``} ` `        ``} ` `         `  `        ``// Loop for print the matrix elements. ` `        ``for` `(``int` `i = ``0``; i < n; i++)  ` `        ``{ ` `            ``for` `(``int` `j = ``0``; j < n; j++) ` `                ``System.out.print( arr[i][j] +``" "``); ` `                ``System.out.println(); ` `        ``} ` `         `  `    ``} ` `     `  `    ``// Driver code ` `    ``public` `static` `void` `main (String[] args)  ` `    ``{ ` `        ``int` `arr[][] = { { ``2``, ``3``, ``5``, ``6` `}, ` `                        ``{ ``4``, ``5``, ``7``, ``9` `}, ` `                        ``{ ``8``, ``6``, ``4``, ``9` `}, ` `                        ``{ ``1``, ``3``, ``5``, ``6` `} }; ` ` `  `        ``// Function call ` `        ``swapUpperToLower(arr); ` `             `  `    ``} ` `} ` ` `  `// This code is contributed by vt_m. `

## Python 3

 `# Python Program to implement matrix ` `# for swapping the upper diagonal ` `# elements with lower diagonal  ` `# elements of matrix. ` ` `  `# Function to swap the diagonal  ` `# elements in a matrix. ` `def` `swapUpperToLower(arr): ` `    ``n ``=` `4``; ` `     `  `    ``# Loop for swap the elements ` `    ``# of matrix. ` `    ``for` `i ``in` `range``(``0``, n):  ` `        ``for` `j ``in` `range``(i ``+` `1``, n):  ` `            ``temp ``=` `arr[i][j]; ` `            ``arr[i][j] ``=` `arr[j][i]; ` `            ``arr[j][i] ``=` `temp; ` `         `  `    ``# Loop for print the matrix elements. ` `    ``for` `i ``in` `range``(``0``, n):  ` `        ``for` `j ``in` `range``(``0``, n):  ` `            ``print``(arr[i][j], end ``=` `" "``); ` `        ``print``(``" "``); ` `     `  `# Driver Code ` ` `  `arr ``=` `[[``2``, ``3``, ``5``, ``6` `],[ ``4``, ``5``, ``7``, ``9` `], ` `       ``[``8``, ``6``, ``4``, ``9` `],[ ``1``, ``3``, ``5``, ``6` `]]; ` ` `  `# Function call ` `swapUpperToLower(arr); ` ` `  `# This code is contributed  ` `# by Shivi_Aggarwal  `

## C#

 `// C# Program to implement matrix ` `// for swapping the upper diagonal ` `// elements with lower diagonal  ` `// elements of matrix. ` `using` `System; ` ` `  `class` `GFG ` `{ ` `    ``static` `int` `n = 4; ` `     `  `    ``// Function to swap the diagonal  ` `    ``// elements in a matrix. ` `    ``static` `void` `swapUpperToLower(``int` `[,]arr) ` `    ``{ ` `        ``// Loop for swap the elements of matrix. ` `        ``for` `(``int` `i = 0; i < n; i++)  ` `        ``{ ` `            ``for` `(``int` `j = i + 1; j < n; j++)  ` `            ``{ ` `                ``int` `temp = arr[i, j]; ` `                ``arr[i, j] = arr[j, i]; ` `                ``arr[j, i] = temp; ` `            ``} ` `        ``} ` `         `  `        ``// Loop for print the matrix elements. ` `        ``for` `(``int` `i = 0; i < n; i++)  ` `        ``{ ` `            ``for` `(``int` `j = 0; j < n; j++) ` `                ``Console.Write(arr[i, j] +``" "``); ` `                ``Console.WriteLine(); ` `        ``} ` `         `  `    ``} ` `     `  `    ``// Driver code ` `    ``public` `static` `void` `Main ()  ` `    ``{ ` `        ``int` `[,]arr = {{ 2, 3, 5, 6 }, ` `                      ``{ 4, 5, 7, 9 }, ` `                      ``{ 8, 6, 4, 9 }, ` `                      ``{ 1, 3, 5, 6 }}; ` ` `  `        ``// Function call ` `        ``swapUpperToLower(arr); ` `             `  `    ``} ` `} ` ` `  `// This code is contributed by vt_m. `

## PHP

 ` `

Output :

```2 4 8 1
3 5 6 3
5 7 4 5
6 9 9 6
```

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Improved By : vt_m, jit_t, Shivi_Aggarwal

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