题解 | 上三角矩阵判定
上三角矩阵判定
https://www.nowcoder.com/practice/f5a29bacfc514e5a935723857e1245e4
def is_upper_triangular(matrix):
n = len(matrix)
for i in range(n):
for j in range(i):
if matrix[i][j] != 0:
return "NO"
return "YES"
n = int(input())
matrix = [list(map(int, input().split())) for _ in range(n)]
print(is_upper_triangular(matrix))
