Print a given matrix in counter-clockwise spiral form in C++

In this problem, we are given a 2-dimensional matrix. And our task is to print the elements of the matrix in a counter-clockwise spiral from.

Counterclockwise Spiral Form − It is a spiral traversal which starts from top-left and the goes in the counter-clockwise direction to first bottom-right-up-left.

The counter-clockwise traversal will be 1 5 9 13 14 15 16 12 8 4 3 2 6 10 11 7.

Let’s take an example to understand the problem

Input:
   2 4 6
   1 7 9
   5 0 3
Output: 2 1 5 0 3 9 7

To solve this problem, we will be using four loops and each in one direction and initializing their direction and traversing accordingly.

Example

Program to show the implementation of our solution

 Live Demo

#include <bits/stdc++.h>
using namespace std;
#define R 3
#define C 3
void printCounterClockwiseSpiral(int m, int n, int matrix[R][C]){
   int i, k = 0, l = 0;
   int count = 0;
   int total = m * n;
   while (k < m && l < n){
      if (count == total)
         break;
      for (i = k; i < m; ++i){
         cout<<matrix[i][l]<<" ";
         count++;
      }
      l++;
      if (count == total)
         break;
      for (i = l; i < n; ++i){
         cout<<matrix[m - 1][i]<<" ";
         count++;
      }
      m--;
      if (count == total)
         break;
      if (k < m){
         for (i = m - 1; i >= k; --i){
            cout<<matrix[i][n - 1]<<" ";
            count++;
         }
         n--;
      }
      if (count == total)
         break;
      if (l < n){
         for (i = n - 1; i >= l; --i){
            cout<<matrix[k][i]<<" ";
            count++;
         }
         k++;
      }
   }
}
int main() {
   int mat[R][C] = {
      { 1, 2, 3 },
      { 4, 5, 6 },
      { 7, 8, 9}
   };
   cout<<"Conter Clockwise Spiral from of the matrix is :\n";
   printCounterClockwiseSpiral(R, C, mat);
   return 0;
}

Output

Counter Clockwise Spiral from of the matrix is −

1 4 7 8 9 6 3 2 5