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0132-分割回文串II

作者:互联网

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:

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

标签:return,0132,range,len,II,length,startIndex,dp,回文
来源: https://www.cnblogs.com/davis12/p/15647419.html