Answer to Question #212625 in Python for sudheer

Question

Given a matrix of order M*N and a value K, write a program to rotate each ring of the matrix clockwise by K elements. If in any ring has less than or equal to K elements, then don’t rotate that ring.

For example, if the given M and N are 4 and 4 respectively. If the matrix elements are

1 2 3 4

5 6 7 8

9 10 11 12

13 14 15 16

If the given K is 3. Rotate each ring of the matrix by 3 elements.

In the above matrix, the elements (1, 2, 3, 4, 8, 12, 16, 15, 14, 13, 9, 5) is a ring, similarly, the elements (6, 7, 11, 10) will make a ring.

Therefore, by rotating each ring in clockwise direction by 3 elements will give (13, 9, 5, 1, 2, 3, 4, 8, 12, 16, 15, 14) and (10, 6, 7, 11). So the output should be

13 9 5 1

14 7 11 2

15 6 10 3

16 12 8 4

input:4 4

1 2 3 4

5 6 7 8

9 10 11 12

13 14 15 16

3

output should print like this:13 9 5 1

14 7 11 2

15 6 10 3

16 12 8 4

Answer 1

def RorateMatrix(A):
    if(len(A)==0):
        return
    TopRow = 0
    BottomRow = len(A)-1
    LC = 0
    RC = len(A[0])-1
    while LC < RC and TopRow < BottomRow:
        prev = A[TopRow+1][LC]
        for i in range(LC, RC+1):
            curr = A[TopRow][i]
            A[TopRow][i] = prev
            prev = curr
        TopRow = TopRow + 1
        for i in range(TopRow, BottomRow+1):
            curr = A[i][RC]
            A[i][RC] = prev
            prev = curr
        RC = RC - 1
        for i in range(RC, LC-1, -1):
            curr = A[BottomRow][i]
            A[BottomRow][i] = prev
            prev = curr
        BottomRow = BottomRow - 1
        for i in range(BottomRow, TopRow-1, -1):
            curr = A[i][LC]
            A[i][LC] = prev
            prev = curr
        LC = LC + 1
 
    return A
 
# Utility Function
def DispMatrix(A):
    for r in A:
        print(r)


#Case-1
M=4
N=4
K=3
matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]]
print("Case-1: Sample Input-1")
DispMatrix(matrix)
A = matrix
for n in range(0,K):
    A = RorateMatrix(A)
print("Sample Output-1")
DispMatrix(A)


#Case-2
M=3
N=4
K=2
matrix = [[1,2,3,4],[10, 11, 12, 5],[9,8,7,6]]
print("\n\nCase-2: Sample Input-2")
DispMatrix(matrix)
A = matrix
for n in range(0,K):
    A = RorateMatrix(A)
print("Sample Output-2")
DispMatrix(A)