Count digit groupings of a number.java

//User function Template for Java

class Solution
{
   static int help(String str,int index,int preSum,int dp[][]){
	    if(index==str.length())return 1;
	    if(dp[index][preSum]!=-1)return dp[index][preSum];
	    int curSum=0,ans=0;
	    for(int i=index;i<str.length();i++){
	        curSum+=str.charAt(i)-'0';
	        if(curSum>=preSum){
	            ans+=help(str,i+1,curSum,dp);
	        }
	        
	    }
	    return dp[index][preSum]=ans;
	}
    public int TotalCount(String str)
    {
        // Code here
        int n=str.length();
	    int dp[][] = new int[n][901];
	    for(int temp[]:dp)Arrays.fill(temp,-1);
	    return help(str,0,0,dp);
    }
}