# Transpose of a Matrix

Tue Feb 08 2022 07:29:55 GMT+0000 (UTC)

```// Efficient Code : Without Using Auxiliary Array

import java.util.*;
import java.io.*;

class GFG
{
static int n = 4;

static void swap(int mat[][], int i, int j)
{
int temp = mat[i][j];
mat[i][j] = mat[j][i];
mat[j][i] = temp;
}

static void transpose(int mat[][])
{

for(int i = 0; i < n; i++)
for(int j = i + 1; j < n; j++)
swap(mat, i, j);
}

public static void main(String args[])
{
int arr[][] = {{1, 2, 3, 4},
{5, 6, 7, 8},
{9, 10, 11, 12},
{13, 14, 15, 16}};

transpose(arr);

for(int i = 0; i < n; i++)
{
for(int j = 0; j < n; j++)
{
System.out.print(arr[i][j]+" ");
}

System.out.println();
}
}
}

// Naive Code :

static int n = 4;

static void transpose(int mat[][])
{
int temp[][] = new int[n][n];

for(int i = 0; i < n; i++)
for(int j = 0; j < n; j++)
// copy
temp[i][j] = mat[j][i]; // temp[i][j] = mat[i][j];

for(int i = 0; i < n; i++)
for(int j = 0; j < n; j++)
// copy back to original array
mat[i][j] = temp[i][j];

}```
content_copyCOPY

Input : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Output : 1 5 9 13 2 6 10 14 3 7 11 15 4 8 12 16 Input : 1 1 2 2 Output : 1 2 1 2