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

public class Solution {
    public boolean wordBreak(String s, Set<String> wordDict) {
        if(s == null || s.length() == 0) return false;
        boolean valid[] = new boolean[s.length()+1];
        valid[0] = true;
        for(int i = 0; i < s.length(); i++) {
            for(int j = 0; j <= i; j++) {
                if(valid[j] && wordDict.contains(s.substring(j,i+1))) {
                    valid[i+1] = true;
                    break;
                }
            }
        }
        return valid[s.length()];
    }

}