Check if all rows of a matrix are circular rotations of each other in Python

Suppose, we are provided with a matrix of the size n*n, containing integer numbers. We have to find out if all the rows of that matrix are circular rotations of its previous row. In case of first row, it should be a circular rotation of the n-th row.

So, if the input is like

then the output will be True.

To solve this, we will follow these steps −

• concat := blank string
• for i in range 0 to number of rows, do
  • concat := concat concatenate "-" concatenate matrix[0,i]
• concat := concat concatenate concat
• for i in range 1 to size of matrix, do
  • curr_row := blank string
  • for j in range 0 to number of columns, do
    • curr_row := curr_row concatenate "-" concatenate matrix[i,j]
  • if curr_row is present in string concat, then
    • return True
• return False

Example

Let us see the following implementation to get better understanding −

 Live Demo

def solve(matrix) :
   concat = ""
   for i in range(len(matrix)) :
      concat = concat + "-" + str(matrix[0][i])
   concat = concat + concat
   for i in range(1, len(matrix)) :
      curr_row = ""
      for j in range(len(matrix[0])) :
         curr_row = curr_row + "-" + str(matrix[i][j])
      if (concat.find(curr_row)) :
         return True
   return False
matrix = [['B', 'A', 'D', 'C'],
         ['C', 'B', 'A', 'D'],
         ['D', 'C', 'B', 'A'],
         ['A', 'D', 'C', 'B']]
print(solve(matrix))

Input

[['B', 'A', 'D', 'C'],
['C', 'B', 'A', 'D'],
['D', 'C', 'B', 'A'],
['A', 'D', 'C', 'B']]

Output

True

Arnab Chakraborty

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Updated on: 18-Jan-2021

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