A square n×n matrix of integers can be written in Python as a list with n elements, where each element is in turn a list of n integers, representing a row of the matrix. For instance, the matrix
1 2 3
4 5 6
7 8 9
would be represented as [[1,2,3], [4,5,6], [7,8,9]].
Write a function leftrotate(m) that takes a list representation m of a square matrix as input, and returns the matrix obtained by rotating the original matrix counterclockwize by 90 degrees. For instance, if we rotate the matrix above, we get
3 6 9
2 5 8
1 4 7
Answers
Answer:
def leftrotate(m):
N = len(m[0])
for x in range(0, int(N / 2)):
for y in range(x, N-x-1):
temp = m[x][y]
m[x][y] = m[y][N-1-x]
m[y][N-1-x] = m[N-1-x][N-1-y]
m[N-1-x][N-1-y] = m[N-1-y][x]
m[N-1-y][x] = temp
return(m)
Explanation: I hope this helps
Explanation:
Provided that:
The given square matrix is:
A = [[1,2,3], [4,5,6], [7,8,9]]
To rotate this matrix we can use Transpose of Matrix;
The driver code to get the transpose of Matrix:
Program Input:
M=int(input("Enter M : "))
N=int(input("Enter N : "))
def transpose(A, B):
for i in range(N):
for j in range(M):
B[i][j] = A[j][i]
print('Insert elemnts of [A]')
a=[int(input()) for i in range(N)]
b=[int(input()) for i in range(N)]
c=[int(input()) for i in range(N)]
print('Matrix A=')
A=[a
,b,
c]
for row in A:
print(row)
print("\n")
print('Order of Matrix [A] :',M,'×',N)
B = [[0 for x in range(M)] for y in range(N)]
transpose(A, B)
print( )
print("Result matrix is [A`] =")
for i in range(N):
for j in range(M):
print(B[i][j], " ", end='')
print()
print( )
print('Order of Matrix [A`] :',N,'×',M)
Program Output:
Enter M : 3
Enter N : 3
Insert elemnts of [A]
1
2
3
4
5
6
7
8
9
Matrix A=
[1, 2, 3]
[4, 5, 6]
[7, 8, 9]
Order of Matrix [A] : 3 × 3
Result matrix is [A`] =
1 4 7
2 5 8
3 6 9
Order of Matrix [A`] : 3 × 3
[Program finished]
Hence by this python programming code we can easily rotate any square matrix (even any matrix) at 90° angle in clockwise direction.
The image of output of this program is given as attachment.
