Word Break Solution using dp memoization

Problem statement
You are given a list of “N” strings array. Your task is to check whether you can form a given target string using a combination of one or more strings of array.

Note :
You can use any string of array multiple times.
Examples :
array =[“dev”, ”porta”, “is”, “awesome”]  target = “devporta”
Ans = true as we use “dev” and “porta” to form “devporta”




import java.util.* ;
import java.io.*; 
public class Solution {
    public static Boolean wordBreak(String[] arr, int n, String target) {
        if(target.isEmpty())
           return true;

        int[] dp = new int[target.length()+1];
        Arrays.fill(dp, -1);
        return findAns(Arrays.asList(arr), n, target, dp);
    }

    public static Boolean findAns(List<String> arr, int n, String target, int[] dp){
         if(target.isEmpty()){
             dp[0] = 1;
             return true;
         }

         int length = target.length();

         if(dp[length]!=-1)
           return dp[length]==1;

        for(int i=1;i<=length;i++){
            String word = target.substring(0,i);
            if(arr.contains(word)){
                Boolean ans = findAns(arr, n, target.substring(i), dp);
                if(ans){
                    dp[length] = 1;
                    break;
                }else{
                    dp[length] = 0;
                }
            }else{
                dp[length] = 0;
            }
        }
        return dp[length]==1;
    }
}