上三角_python3
KiKi判断上三角矩阵
http://www.nowcoder.com/questionTerminal/9a6786c28cdb45f9b991685f867b5d08
n = int(input())
l = []
for i in range(n):
l.extend(list(map(int, input().split())))
for i in range(n):
for j in range(n):
if i > j and l[i*n+j]:
print('NO')
break
else:
continue
break
else:
print('YES')
