Transpose of Matrix

Problem Statement - link #

Write a program to find the transpose of a square matrix of size N*N. Transpose of a matrix is obtained by changing rows to columns and columns to rows.

Your Task: You dont need to read input or print anything. Complete the function transpose() which takes matrix[][] and N as input parameter and finds the transpose of the input matrix. You need to do this in-place. That is you need to update the original matrix with the transpose.

Expected Time Complexity: O(N*N)
Expected Auxiliary Space: O(1)

Examples #

Example 1:

Input:
N = 4
mat[][] = [[1, 1, 1, 1], [2, 2, 2, 2], [3, 3, 3, 3], [4, 4, 4, 4]]
Output: 
[[1, 2, 3, 4], [1, 2, 3, 4], [1, 2, 3, 4], [1, 2, 3, 4]] 

Example 2:

Input:
N = 2
mat[][] = [[1, 2], [-9, -2]]
Output:
[[1, -9],  [2, -2]]

Constraints #

• 1 <= N <= 100
• -1000 <= matrix[i][j] <= 1000

Solutions #

class Solution{
    public:
    //Function to find transpose of a matrix.
    void transpose(vector<vector<int> >& matrix, int n)
    { 
        // code here 
        for(int i=0; i<n; i++)
            for(int j=i+1; j<n; j++)
                swap(matrix[i][j], matrix[j][i]);
    }

};