https://leetcode.com/problems/palindrome-partitioning-ii/description/ [题意] 给定一个字符串,求最少切割多少下,使得切割后的每个子串都是回文串 [思路] 求一个字符串的所有子串是否是回文串,O(n^2) dp从后往前推 vector<vector<bool> > p(len,vector<bool>(len)); ;i<len-;i++){ ;j<len-;j++){ if(j!=i)…

Palindrome Partitioning II  Given a string s, partition s such that every substring of the partition is a palindrome. Return the minimum cuts needed for a palindrome partitioning of s. For example, given s = "aab",Return 1 since the palindrome p…

131. Palindrome Partitioning substr使用的是坐标值,不使用.begin()..end()这种迭代器 使用dfs,类似于subsets的题,每次判断要不要加入这个数 start每次是起始的位置,判断当前位置到起始位置是不是回文 class Solution { public: vector<vector<string>> partition(string s) { vector<vector<string> > result;…

Given a string s, partition s such that every substring of the partition is a palindrome. Return the minimum cuts needed for a palindrome partitioning of s. For example, given s = "aab",Return 1 since the palindrome partitioning ["aa",…

Given a string s, partition s such that every substring of the partition is a palindrome. Return the minimum cuts needed for a palindrome partitioning of s. For example, given s = "aab",Return 1 since the palindrome partitioning ["aa",…

Given a string s, partition s such that every substring of the partition is a palindrome. Return the minimum cuts needed for a palindrome partitioning of s. For example, given s = "aab", Return 1 since the palindrome partitioning ["aa"…

题目: Given a string s, partition s such that every substring of the partition is a palindrome. Return the minimum cuts needed for a palindrome partitioning of s. For example, given s = "aab",Return 1 since the palindrome partitioning ["aa&qu…

求次数的问题一般用DP class Solution(object): def minCut(self, s): """ :type s: str :rtype: int """ n = len(s) maxInt = 2147483647 cuts = [maxInt for x in range(n)] p = self.palinTable(s) for i in range(n): temp = maxInt if p[0][i] ==…

https://leetcode.com/problems/k-inverse-pairs-array/description/ [题意] 给定n和k,求正好有k个逆序对的长度为n的序列有多少个,0<=k<=1000, 1<=n<=1000,答案模1e9+7 [思路] dp[i][j]表示正好有j个逆序对的长度为i的序列的方案数,最终我们要求的就是dp[n][k] 考虑dp[i+1][j]和dp[i][j]的关系,长度为i+1的序列相当于在长度为i的序列中插入一个数,那么有 xxx…

https://leetcode.com/problems/dungeon-game/description/ [题意] 给定m*n的地牢,王子初始位置在左上角,公主在右下角不动,王子要去救公主,每步只能往右或往下走一格.每个格子是一个整数,负数代表生命值减掉相应分数,正数表示生命值增加相应分值,要保证王子在走的过程中不挂掉,即经过每个格子后的生命值大于等于1,问王子最初的生命值最少是多少. [思路] 倒着推dp,计算(i,j)->(m,n)的可生存血量. dp[i][j]=max(1,min(…