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>

void Set(int a[3], int max, int mid, int min){
  a[0] = max;
  a[1] = mid;
  a[2] = min;
}

int Count(int a[3], int N){
  int i, j, k, I, J, K, c;
  c = 0;
  for(i = N / a[0];i >= 0;i--){
    I = i * a[0];
    for(j = N - I;j >= 0;j--){
      J = j * a[1];
      for(k = N - I - J;k >= 0;k--){
	K = k * a[2];
	if(I + J + K == N) c++;
      }
    }
  }
  return c;
}

int main(void){
  int R, G, B, N;
  int a[3];
  scanf("%d %d %d %d", &R, &G, &B, &N);
  if(R > G){
    if(G > B) Set(a, R, G, B);
    else{
      if(R > B) Set(a, R, B, G);
      else Set(a, B, R, G);
    }
  }else{
    if(R > B) Set(a, G, R, B);
    else{
      if(G > B) Set(a, G, B, R);
      else Set(a, B, G, R);
    }
  }
  printf("%d\n", Count(a, N));
  return 0;
}