给你一个字符串 s,请你将 s 分割成一些子串,使每个子串都是回文。
返回符合要求的 最少分割次数 。
示例 1:
输入:s = "aab"
输出:1
解释:只需一次分割就可将 s 分割成 ["aa","b"] 这样两个回文子串。
示例 2:
输入:s = "a"
输出:0
示例 3:
输入:s = "ab"
输出:1
提示:
1 <= s.length <= 2000
s 仅由小写英文字母组成
来源:力扣(LeetCode)
链接:https://leetcode-cn.com/problems/palindrome-partitioning-ii
参考:
- 官方
python
# 0132.分割回文串II
class Solution:
def minCut(self, s: str) -> int:
"""
动态规划
:param s:
:return:
"""
length = len(s)
dp = [[True] * length for _ in range(length)]
for i in range(length-1, -1, -1):
for j in range(i+1, length):
dp[i][j] = (s[i]==s[j]) and dp[i+1][j-1]
f = [float("INF")] * length
for i in range(length):
if dp[0][i]:
f[i] = 0
else:
for j in range(i):
if dp[j+1][i]:
f[i] = min(f[i], f[j]+1)
return f[length-1]
def minCut_(self, s: str) -> int:
"""
参考题131, 回溯法超时间
:param s:
:return:
"""
res = []
path = []
def isPalindrome(s):
n = len(s)
i, j = 0, n - 1
while i < j:
if s[i] != s[j]: return False
i += 1
j -= 1
return True
def track(s, startIndex):
# 起始位置已经大于s的大小,说明已经找到一组分割方案
if startIndex >= len(s):
res.append(path[:])
return
for i in range(startIndex, len(s)):
# 获取[startIndex:i+1]的子串
p = s[startIndex:i + 1]
if isPalindrome(p):
path.append(p)
else:
continue
track(s, i + 1)
path.pop() # 回溯
track(s, 0)
MIN = 10000
for item in res:
length = len(item)
MIN = min(MIN, length-1)
return MIN
golang
待完善