Spiral matrix

[SoumyadeepMukherjee]

What is a Spiral matrix?

[abirbhattacharya82]

The Spiral Matrix problem takes a 2-Dimensional array of N-rows and M-columns as an input, and prints the elements of this matrix in spiral order.

The spiral begins at the top left corner of the input matrix, and prints the elements it encounters, while looping towards the center of this matrix, in a clockwise manner.​

Sample Code in python

def spiralMatrixPrint(row, col, arr):
    # Defining the boundaries of the matrix.
    top = 0
    bottom = row-1
    left = 0
    right = col - 1

    # Defining the direction in which the array is to be traversed.
    dir = 0
    
    while (top <= bottom and left <=right):    
        if dir ==0:
            for i in range(left,right+1): # moving left->right
                print (arr[top][i], end=" ")

            # Since we have traversed the whole first
            # row, move down to the next row.
            top +=1
            dir = 1

        elif dir ==1:
            for i in range(top,bottom+1): # moving top->bottom
                print (arr[i][right], end=" ")

            # Since we have traversed the whole last
            # column, move down to the previous column.
            right -=1 
            dir = 2
            
        elif dir ==2:
            for i in range(right,left-1,-1): # moving right->left
                print (arr[bottom][i], end=" ")

            # Since we have traversed the whole last
            # row, move down to the previous row.
            bottom -=1
            dir = 3
            
        elif dir ==3:
            for i in range(bottom,top-1,-1): # moving bottom->top
                print (arr[i][left], end=" ")
            # Since we have traversed the whole first
            # column, move down to the next column.
            left +=1
            dir = 0

# Driver code
# Change the following array and the corresponding row and
# column arguments to test on some other input
array = [[1,2,3,4],
     [12,13,14,5],
     [11,16,15,6],
     [10,9,8,7]]

spiralMatrixPrint(4, 4, array)