Word Break

Given a string s and a dictionary of words dict, determine if s can be segmented into
a space-separated sequence of one or more dictionary words.
For example, given
s = "leetcode",
dict = ["leet", "code"].
Return true because "leetcode" can be segmented as "leet code".

Solution: dp.

 1 class Solution {
 2 public:
 3     
 4     bool wordBreak(string s, unordered_set<string> &dict) {
 5         int N = s.length();
 6         vector<bool> canBreak(N+1,false);
 7         canBreak[0] = true;
 8         for (int i = 1; i <= N; i++) {
 9             for (int j = i-1; j >= 0; j--) {
10                 if (canBreak[j] && dict.find(s.substr(j,i-j)) != dict.end()) {
11                     canBreak[i] = true;
12                     break;
13                 }
14             }
15         }
16         return canBreak[N];
17     }
18 };

 

转载于:https://www.cnblogs.com/zhengjiankang/p/3659898.html