Inplace rotate square matrix by 90 degrees by forming cycles

#include <bits/stdc++.h>
#define N 4
using namespace std;
 
// An Inplace function to
// rotate a N x N matrix
// by 90 degrees in
// anti-clockwise direction
void rotateMatrix(int mat[][N])
{
    // Consider all squares one by one
    for (int x = 0; x < N / 2; x++) {
        // Consider elements in group
        // of 4 in current square
        for (int y = x; y < N - x - 1; y++) {
            // Store current cell in
            // temp variable
            int temp = mat[x][y];
 
            // Move values from right to top
            mat[x][y] = mat[y][N - 1 - x];
 
            // Move values from bottom to right
            mat[y][N - 1 - x] = mat[N - 1 - x][N - 1 - y];
 
            // Move values from left to bottom
            mat[N - 1 - x][N - 1 - y] = mat[N - 1 - y][x];
 
            // Assign temp to left
            mat[N - 1 - y][x] = temp;
        }
    }
}
 
// Function to print the matrix
void displayMatrix(int mat[N][N])
{
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            cout << mat[i][j] << " ";
        }
        cout << endl;
    }
    cout << endl;
}
 
/* Driver code */
int main()
{
    // Test Case 1
    int mat[N][N] = { { 1, 2, 3, 4 },
                      { 5, 6, 7, 8 },
                      { 9, 10, 11, 12 },
                      { 13, 14, 15, 16 } };
 
    // Function call
    rotateMatrix(mat);
 
    // Print rotated matrix
    displayMatrix(mat);
 
    return 0;
}