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.util.*;

class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int r = Integer.parseInt(sc.next());
    int g = Integer.parseInt(sc.next());
    int b = Integer.parseInt(sc.next());
    int n = Integer.parseInt(sc.next());

    int res = 0;
    int total = 0;
    
    for (int x = 0; x <= n/r; x++) {
      if (r*x <= n) {
        for (int y = 0; y <= n/g; y++) {
          if (r*x+g*y <= n) {
            total = n - r*x - g*y;
            if (total%b == 0) {
              res++;
            }
          }
        }
      }
    }
    
    System.out.println(res);
  }
}