class Solution {
    public boolean wordBreak(String s, List<String> wordDict) {

        Set<String> allWords=new HashSet<>(wordDict);
        int n=wordDict.size();
        int m=s.length();
        boolean [] dp=new boolean[m+1];
        dp[0]=true;
        for(int i=1;i<=m;++i){
            for(int j=0;j<i;++j){
                if(dp[j] && allWords.contains(s.substring(j,i))){
                    dp[i]=true;
                    break;
                }
            }
        }
        return dp[m];
    }
}