代码随想录——139.单词拆分

class Solution {
    public boolean wordBreak(String s, List<String> wordDict) {
        HashSet<String> set = new HashSet<>(wordDict);
        boolean[] valid = new boolean[s.length() + 1];
        valid[0] = true;

        for(int i = 1;i<= s.length();i++){
            for(int j = 0;j<i && !valid[i];j++){
                if(set.contains(s.substring(j,i))&&valid[j]){
                    valid[i]=true;
                }
            }
        }
        return valid[s.length()];
    }
}