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: Time Limit Exceeded)

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(){

  int r, g, b, n;
  int cnt_r=0, cnt_g=0, cnt_b=0;
  int ans = 0;
  
  scanf("%d%d%d%d", &r, &g, &b, &n);
  
  cnt_r = n / r;
  cnt_g = n / g; 
  cnt_b = n / b;
  for(int i = 0; i <= cnt_r; i++){
    for(int j = 0; j <= cnt_g; j++){
      for(int k = 0; k <= cnt_b; k++){
	if((r*i + g*j + b*k) == n){
	  ans++;
	}
      }
    }

  }

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

  return 0;
}