Python Program to Print a given matrix in reverse spiral form
Given a 2D array, print it in reverse spiral form. We have already discussed Print a given matrix in spiral form. This article discusses how to do the reverse printing. See the following examples.
Input:
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
Output:
10 11 7 6 5 9 13 14 15 16 12 8 4 3 2 1
Input:
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
Output:
11 10 9 8 7 13 14 15 16 17 18 12 6 5 4 3 2 1
Python3
# Python3 Code to Print a given # matrix in reverse spiral form # This is a modified code of# https:#www.geeksforgeeks.org/print-a-given-matrix-in-spiral-form/R, C = 3, 6 def ReversespiralPrint(m, n, a): # Large array to initialize it # with elements of matrix b = [0 for i in range(100)] #/* k - starting row index #l - starting column index*/ i, k, l = 0, 0, 0 # Counter for single dimension array # in which elements will be stored z = 0 # Total elements in matrix size = m * n while (k < m and l < n): # Variable to store value of matrix. val = 0 # Print the first row # from the remaining rows for i in range(l, n): # printf("%d ", a[k][i]) val = a[k][i] b[z] = val z += 1 k += 1 # Print the last column # from the remaining columns for i in range(k, m): # printf("%d ", a[i][n-1]) val = a[i][n - 1] b[z] = val z += 1 n -= 1 # Print the last row # from the remaining rows if (k < m): for i in range(n - 1, l - 1, -1): # printf("%d ", a[m-1][i]) val = a[m - 1][i] b[z] = val z += 1 m -= 1 # Print the first column # from the remaining columns if (l < n): for i in range(m - 1, k - 1, -1): # printf("%d ", a[i][l]) val = a[i][l] b[z] = val z += 1 l += 1 for i in range(size - 1, -1, -1): print(b[i], end = " ") # Driver Codea = [[1, 2, 3, 4, 5, 6], [7, 8, 9, 10, 11, 12], [13, 14, 15, 16, 17, 18]] ReversespiralPrint(R, C, a) # This code is contributed by mohit kumar |
Output:
11 10 9 8 7 13 14 15 16 17 18 12 6 5 4 3 2 1
Please refer complete article on Print a given matrix in reverse spiral form for more details!
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