Python源码:
def triangle(row):
alphabet = ['%c' % i for i in range(65, 65+26)]
for i in range(1, row+1):
if i <= 26:
string = ''.join(alphabet[:i] + list(reversed(alphabet[:i-1])))
else:
j = i - 26
string = alphabet[:] + alphabet[:j] + list(reversed(alphabet[:] + alphabet[:j-1]))
string = ''.join(string)
print(' ' * (row-i) + string)
triangle(28)