osigmao的专栏

public class Solution { public List> combinationSum(int[] candidates, int target) { if (candidates == null || candidates.length == 0) { return null; } Arrays.so

1, Given a list of N coins, their values (V1, V2, ... , VN), and the total sum S. Find the minimum number of coins the sum of which is S (we can use as many coins of one type as we want), or r

枚举的题，一般用DFS+Backtracking做，此题会超时，那么要辅助memoization, 保存之前得到的结果.怎么mem？1，借鉴word break I, 保存能否该index之后能否break： boolean[s.length() + 1]2,  保存详细的分法结果： HashMap>public class Solution { List res =

public class Solution { public String longestPalindrome(String s) { if (s == null) return null; int max = 0; String maxSub = ""; for (int beg = 0; beg < s.length();

Given two words word1 and word2, find the minimum number of steps required to convert word1 to word2. (each operation is counted as 1 step.)You have the following 3 operations permitted on a word:

1, recursion2, recursion + memoization3, DP

最值问题的第二种思路，保存局部最优，更新全局最优求P

先保存一下 某个大神的DP专辑：http://www.cnblogs.com/remlostime/tag/DP/