Check if All Non-Border Elements in 4×4 Matrix Are "Yes"

Program Overview

This Python program reads a 4×4 matrix and checks whether all non-border elements are equal to the string "Yes".
Border elements include the first and last rows and columns.
If all inner elements are "Yes", it prints "Yes"; otherwise, it prints "No".

Python Code:

def read_matrix(n: int) -> list[list[str]]:
    print(f"Enter elements for a {n}×{n} matrix:")
    matrix = []
    for i in range(n):
        row = input(f"Row {i+1}: ").strip().split()
        if len(row) != n:
            print("Each row must contain exactly n elements.")
            exit()
        matrix.append(row)
    return matrix

def check_inner_yes(matrix: list[list[str]]) -> str:
    n = len(matrix)
    for i in range(1, n - 1):
        for j in range(1, n - 1):
            if matrix[i][j] != "Yes":
                return "No"
    return "Yes"

# Read and check 4×4 matrix
mat = read_matrix(4)
result = check_inner_yes(mat)
print(f"\nCheck result: {result}")

Sample Output:

Input:  
No No No No  
No Yes Yes No  
No Yes Yes No  
No No No No  

Output:  
Check result: Yes