Problem:
Score : 200 points

Problem Statement

Snuke has come to a store that sells boxes containing balls. The store sells the following three kinds of boxes:

Red boxes, each containing R red balls

Green boxes, each containing G green balls

Blue boxes, each containing B blue balls

Snuke wants to get a total of exactly N balls by buying r red boxes, g green boxes and b blue boxes.
How many triples of non-negative integers (r,g,b) achieve this?

Constraints

All values in input are integers.

1 \leq R,G,B,N \leq 3000

Input

Input is given from Standard Input in the following format:

R G B N

Output

Print the answer.

Sample Input 1

1 2 3 4

Sample Output 1

4

Four triples achieve the objective, as follows:

(4,0,0)

(2,1,0)

(1,0,1)

(0,2,0)

Sample Input 2

13 1 4 3000

Sample Output 2

87058

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.List;

public class Main {
	static List<Integer> path;

	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] sa = br.readLine().split(" ");
		int r = Integer.parseInt(sa[0]);
		int g = Integer.parseInt(sa[1]);
		int b = Integer.parseInt(sa[2]);
		int n = Integer.parseInt(sa[3]);
		br.close();

		long ans = 0;
		int rr = n / r;
		int gg = n / g;
		for (int i = 0; i <= rr; i++) {
			int num = r * i;
			for (int j = 0; j <= gg; j++) {
				num += g * j;
				if (num > n) {
					break;
				}
				if ((n - num) % b == 0) {
					ans++;
				}
				num -= g * j;
			}
		}
		System.out.println(ans);
	}
}