Given a matrix mat[][] of dimensions M * N, the task is to print the matrix obtained after rotating every ith row of the matrix i times in a clockwise direction.
Examples:
Input: mat[][] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}
Output:
1 2 3
6 4 5
8 9 7
Explanation:
The 0th row is rotated 0 times. Therefore, the 0th row remains the same as {1, 2, 3}.
The 1st row is rotated 1 times. Therefore, the 1st row modifies to {6, 4, 5}.
The 2nd row is rotated 2 times. Therefore, the 2nd row modifies to {8, 9, 7}.
After completing the above operations, the given matrix modifies to {{1, 2, 3}, {6, 4, 5}, {8, 9, 7}}.Input: mat[][] = {{1, 2, 3, 4}, {4, 5, 6, 7}, {7, 8, 9, 8}, {7, 8, 9, 8}}
Output:
1 2 3 4
7 4 5 6
9 8 7 8
8 9 8 7
Approach: Follow the steps below to solve the problem:
-
Traverse the given matrix in row – wise manner and for every ith row, perform the following steps:
- Reverse the current row of the matrix.
- Reverse the first i elements of the current row.
- Reverse the last (N – i) elements of the current row, where N is the current size of the row.
- After completing the above steps, print the matrix mat[][].
Below is the implementation of the above approach:
# Python3 program for the above approach # Function to rotate every i-th # row of the matrix i times def rotateMatrix(mat):
i = 0
mat1 = []
# Traverse the matrix row-wise
for it in mat:
# Reverse the current row
it.reverse()
# Reverse the first i elements
it1 = it[:i]
it1.reverse()
# Reverse the last (N - i) elements
it2 = it[i:]
it2.reverse()
# Increment count
i + = 1
mat1.append(it1 + it2)
# Print final matrix
for rows in mat1:
for cols in rows:
print (cols, end = " " )
print ()
# Driver Code if __name__ = = "__main__" :
mat = [ [ 1 , 2 , 3 ], [ 4 , 5 , 6 ], [ 7 , 8 , 9 ] ]
rotateMatrix(mat)
# This code is contributed by ukasp |
1 2 3 6 4 5 8 9 7
Time Complexity: O(N*M), as we are using nested loops to traverse N*M times.
Auxiliary Space: O(1), as we are not using any extra space.
Please refer complete article on Modify a matrix by rotating ith row exactly i times in clockwise direction for more details!