CF- Good Subarrays Question

Problems and Contests
#1

Problem

My idea is to subtract 1 from all the elements. Then in order for a subarray of numbers to satisfy the conditions, the numbers in the subarray have to sum to 0, since there are l-r+1 elements between l and r. So I made a prefix sum array for the numbers after subtracting 1 from all the elements, but that didn’t work. Where did I go wrong?

import java.io.*;
import java.util.HashMap;
import java.util.StringTokenizer;

public class GoodSubarrays {
    public static void main(String args[]) {
        Kattio io = new Kattio();
        int numCases = io.nextInt();
        for (int c = 0; c<numCases; c++) {
            int arraySize = io.nextInt();
            long[] nums = new long[arraySize];
            String sequence = io.next();

            long total = 0;
            for (int i = 0; i<sequence.length(); i++) {
                nums[i] = Long.valueOf("" + sequence.charAt(i))-(long)1;
                if (nums[i] == 0) {
                    total++;
                }
            }
            HashMap<Long, Long> valueCounts = new HashMap<>(); //value, count
            for (int i = 1; i<nums.length; i++) {
                nums[i] = nums[i] + nums[i-1];
                if (nums[i] == 0 && i!=0) {
                    total++;
                }
                if (valueCounts.containsKey(nums[i])) {
                    valueCounts.put(nums[i], valueCounts.get(nums[i])+1);
                }
                else {
                    valueCounts.put(nums[i], (long)1);
                }
            }

            //A - B = 0
            for (Long i : valueCounts.keySet()) {
                    total += valueCounts.get(i)*(valueCounts.get(i)-1)/2;
            }
            io.println(total);
         }
        io.close();
    }
    static class Kattio extends PrintWriter {
        private BufferedReader r;
        private StringTokenizer st;
        // standard input
        public Kattio() { this(System.in, System.out); }
        public Kattio(InputStream i, OutputStream o) {
            super(o);
            r = new BufferedReader(new InputStreamReader(i));
        }
        // USACO-style file input
        public Kattio(String problemName) throws IOException {
            super(problemName + ".out");
            r = new BufferedReader(new FileReader(problemName + ".in"));
        }
        // returns null if no more input
        public String next() {
            try {
                while (st == null || !st.hasMoreTokens())
                    st = new StringTokenizer(r.readLine());
                return st.nextToken();
            } catch (Exception e) { }
            return null;
        }
        public int nextInt() { return Integer.parseInt(next()); }
        public double nextDouble() { return Double.parseDouble(next()); }
    }
}
#2