62.leetCode131: Palindrome Partitioning【列表划分的回文判断】

【题目】：

Given a string s, partition s such that every substring of the partition is a palindrome.

Return all possible palindrome partitioning of s.

For example, given s = "aab",
Return

[
  ["aa","b"],
  ["a","a","b"]
]

【参考资料】：

leetcode讲解

【Python代码】：回溯，注意移除最后一个元素要用pop()，不要用remove()，不然会出问题

class Solution(object):
    def partition(self, s):
        """
        :type s: str
        :rtype: List[List[str]]
        """
        result = [[]]
        if not s:
            return result
        self.helper(result, [], s)
        return result[1:]

    def helper(self, result, lt, s):
        if len(s) == 0:
            result.append(lt[:])
        for i in range(len(s)):
            if self.isPalindrome(s[0:i+1]):
                lt.append(s[0:i+1])
                self.helper(result, lt, s[i + 1:])
                lt.pop()

    def isPalindrome(self,s):
        left = 0
        right = len(s) - 1
        while left < right:
            if s[left] != s[right]:
                return False
            else:
                left += 1
                right -= 1
        return True