59. Spiral Matrix II

In the very last question, we have done a question where we have to print a 2D matrix in spiral form and in this question, we have to insert values into that 2D matrix from i to n^2.

The approach for this problem would be the same as in the previous question, we will make a 2d vector with all values 0 and the same as in the previous question we will insert values into the array.

 vector<vector<int>> generateMatrix(int n) 
    {
        vector<vector<int>> vec(n,vector<int> (n,0));

        int k=1;

        int srow=0;
        int erow=n-1;

        int scol=0;
        int ecol=n-1;

        while(srow<=erow && scol<=ecol)
        {
            for(int j=scol;j<=ecol;j++)
            {
                vec[srow][j]=k;
                k++;
            }

            for(int j=srow+1;j<=erow;j++)
            {
                vec[j][ecol]=k;
                k++;
            }

            for(int j=ecol-1;j>=scol;j--)
            {
                if(srow==erow)
                {
                    break;
                }

                vec[erow][j]=k;
                k++;
            }

            for(int j=erow-1;j>=srow+1;j--)
            {
                if(scol==ecol)
                {
                    break; 
                }

                vec[j][scol]=k;
                k++;
            }

            srow++;
            scol++;
            erow--;
            ecol--;
        }

        return vec;

    }