0X00 总结
判断回文
def judgePal(s):
left, right = 0, len(s) - 1
while left < right:
if s[left] != s[right]: return False
left += 1
right -= 1
return True
print(judgePal("a"))
print(judgePal("ab"))
print(judgePal("aba"))
print(judgePal("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"))
找到所有回文
O()
def findAllPal(s):
m = len(s)
# 枚举中心点
# 只有上半部分的结果
# res 的下半部分没使用
res = [[False] * m for _ in range(m)]
for center in range(m):
# 偶数长度回文
left, right = center, center + 1
while left > -1 and right < m:
if s[left] != s[right]: break
res[left][right] = True
left, right = left-1, right+1
# 奇数长度回文
left, right = center, center
while left > -1 and right < m:
if s[left] != s[right]: break
res[left][right] = True
left, right = left - 1, right + 1
return res
a = "aabb"
# 只有上半部分
print(findAllPal(a))
