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>

int main(){
        unsigned short r,g,b,n;
        unsigned short x,y,z;
        unsigned short i,j;
        unsigned short ans=0;
        unsigned short count=0;
        scanf("%d %d %d %d", &r, &g, &b, &n);

        if(g<b){
                i = g;
                g = b;
                b = i;
        }
        if(r<g){
                i = r;
                r = g;
                g = i;
        }
        if(g<b){
                i = g;
                g = b;
                b = i;
        }

        x = y = z = 0;


        for(x = n/r; x >= 0 ; x--){
                for(y = (n-(r*x))/g; y >= 0 ; y--){
                        for(z = (n-(r*x)-(g*y))/b; z >= 0 ; z--){
                                if(r*x + g*y + b*z == n) ans++;
                        }
                }
        }

        printf("%d\n",ans);
        return 0;
}