A solution to numrange problem. Problem description and sample input is given with the solution.

NumRange.java

/**
Given an array of non negative integers A, and a range (B, C), 
find the number of continuous subsequences in the array which have sum S in the range [B, C] or B <= S <= C

Continuous subsequence is defined as all the numbers A[i], A[i + 1], .... A[j]
where 0 <= i <= j < size(A)

Input Description: 
First line contains the number of inputs preceding with total number of input
Second line contains B lower range of sum (inclusive)
Third line contains C upper range of sum (inclusive)

Note: The answer is guranteed to fit in a 32 bit signed integer. Following solution doesn't show the technique to read the input.
It assumes inputs are given to the numRange function.

Example:
Input:
5 10 5 1 0 2
6
8

Output:
3

> as [5, 1], [5, 1, 0], [5, 1, 0, 2] are the only 3 continuous subsequence with their sum in the range [6, 8]
==========
Input:
5 80 97 78 45 23
99
269

Output:
7
==========
Input:
1 1
0
0

Output:
0
**/
========================================================================================================================
import java.util.*;

public class NumRange {

    public int numRange(ArrayList<Integer> A, int B, int C) {
        int i = 0, j = 0, freeze = 0, count = 0;
        int len = A.size();
        boolean incJ = false;
        while (i < len) {
            int sum = getSumInRange(A, j, i);
            if (!incJ) {
                if (sum >= B && sum <= C) {
                    count++;
                    freeze = j;
                    j++;
                    incJ = true;
                } else if (sum > C) {
                    j++;
                    if (j > i) {
                        i++;
                    }
                } else {
                    i++;
                }
            } else {
                if (sum < B) {
                    j = freeze;
                    i++;
                    incJ = false;
                } else {
                    count++;
                    j++;
                }
            }
        }
        
        return count;
    }
    
    private int getSumInRange(ArrayList<Integer> A, int sIdx, int eIdx) {
        int sum = 0;
        if (sIdx == eIdx) {
            return A.get(sIdx);
        }
        
        for (int i = sIdx; i <= eIdx; i++) {
            sum += A.get(i);
        }
        return sum;
    }
}