Python程序检查幂等矩阵

给定一个 N * N 矩阵，任务是检查矩阵是否是幂等矩阵。
幂等矩阵： 如果矩阵乘以自身返回相同的矩阵，则称矩阵是幂等矩阵。当且仅当M * M = M时，矩阵 M 被称为幂等矩阵。在幂等矩阵中，M 是一个方阵。

例子：

Input : mat[][] = {{3, -6},
                   {1, -2}};
Output : Idempotent Matrix

Input : mat[N][N] = {{2, -2, -4},
                     {-1, 3, 4},
                     {1, -2, -3}}
Output : Idempotent Matrix.

Python 3

# Python Program to check given matrix 
# is idempotent matrix or not.
import math
  
# Function for matrix multiplication.
def multiply(mat, res):
  
    N= len(mat)
    for i in range(0,N):
      
        for j in range(0,N):
          
            res[i][j] = 0
            for k in range(0,N):
                res[i][j] += mat[i][k] * mat[k][j]
  
# Function to check idempotent
# property of matrix.
def checkIdempotent(mat):
  
    N= len(mat)
    # Calculate multiplication of matrix
    # with itself and store it into res.
    res =[[0]*N for i in range(0,N)]
    multiply(mat, res)
  
    for i in range(0,N):
        for j in range(0,N):     
            if (mat[i][j] != res[i][j]):
                return False
    return True
  
# driver Function
mat = [ [2, -2, -4],
        [-1, 3, 4],
        [1, -2, -3] ]
      
# checkIdempotent function call.
if (checkIdempotent(mat)):
    print("Idempotent Matrix")
else:
    print("Not Idempotent Matrix.")
  
# This code is contributed by Gitanjali.

输出：

Idempotent Matrix

请参阅有关程序的完整文章以检查幂等矩阵以获取更多详细信息！