139.单词拆分 

class Solution {
public:bool wordBreak(string s, vector<string>& wordDict) {unordered_set<string> wordSet(wordDict.begin(), wordDict.end());vector<bool> dp(s.size() + 1, false);dp[0] = true;for (int i = 1; i <= s.size(); i++) {   // 遍历背包for (int j = 0; j < i; j++) {       // 遍历物品string word = s.substr(j, i - j); //substr(起始位置，截取的个数)if (wordSet.find(word) != wordSet.end() && dp[j]) {dp[i] = true;}}}return dp[s.size()];}
};

关于多重背包，你该了解这些！ 

解决方法，0-1背包多加一个遍历即可

背包问题总结篇！