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 C (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>

int main(void){
  int a,b,c,N;
  scanf("%d%d%d%d",&a,&b,&c,&N);

  int ans = 0;
  for (int i = 0; i <= N/a; i++) {
    if(i*a > N) break;
    for (int j = 0; j <= N/b; j++) {
      if(i*a+j*b > N) break;
      if((N-i*a-j*b)%c == 0) ans++;
    }
  }

  printf("%d\n",ans);

  return 0;
}