rotate_complete.cpp

/*
============================================================================
* Author       : Ali Akber Aakash
* Email        : ali852609@gmail.com
* Problem Name : Matrix Rotation
* Source       : Cracking The Coding Interview - Gayle Laakmann McDowell
* Time Limit   : 1.00 sec
============================================================================
*/

#include<bits/stdc++.h>

using namespace std;

int main()
{
//    freopen("input.txt", "r", stdin);
//    freopen("output.txt", "w", stdout);

    //setting up the matrix
    int matrix[4][4]={
        1,2,3,4,
        5,6,7,8,
        9,10,11,12,
        13,14,15,16
    };

    //length of the matrix
    int n = 4;

    //traversing through the layers
    for(int layer=0; layer<n/2; layer++)
    {
        int first = layer;
        int last = n-layer-1;

        //traverse through start to end
        for(int i=first; i<last; i++)
        {
            //creating the offset
            int offset = i - first;

            //storing the top value
            int top = matrix[first][i];

            //store left in top
            matrix[first][i] = matrix[last-offset][first];

            //store bottom in left
            matrix[last-offset][first] = matrix[last][last-offset];

            //store right in bottom
            matrix[last][last-offset] = matrix[i][last];

            //store top in right
            matrix[i][last] = top;
        }
    }

    for(int i=0; i<4; i++)
    {
        for(int j=0; j<4; j++)
            cout<<matrix[i][j]<<" ";
        cout<<endl;
    }

    return 0;
}