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>
#include <string.h>
#include <math.h>
#include <stdlib.h>
#define MOD 998244353
#define MAX(a,b) (a>b?a:b)
#define MAX3(a,b,c) MAX(a,MAX(b,c))
#define MIN(a,b) (a<b?a:b)
#define MIN3(a,b,c) MIN(a, MIN(b,c))
typedef long long lli;
int cmp(const void *a, const void *b) {
    return *(int*)a - *(int*)b;
}

int main()
{
    int R,G,B,n,r=0,g=0,b=0,ans=0;
    scanf("%d%d%d%d",&R,&G,&B,&n);
    for(r=0; r*R<=n; r++) {
        for(g=0; r*R+g*G<=n; g++) {
            if((n-r*R-g*G)%B == 0) {
                ans++;
            }
        }
    }
    printf("%d",ans);
    return 0;
}