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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<iostream>
#include<string>
#include<algorithm>    
#include<cmath>
#include<map>
#include<vector>
#include<math.h>
#include<stdio.h>
#include<stack>
#include<queue>
#include<tuple>
#include<cassert>
#include<set>
//#include<bits/stdc++.h>
#define int long long
using namespace std;
const int INF = 10000000000000000;
const int mod = 1000000007;
int test[12345678], kari[345678], aa[12345678];
signed main() {
	int n, a, b, c, ans = 0; cin >> a >> b >> c >> n;
	for (int h = 0; h <= 3000; h++) {
		for (int i = 0; i <= 3000; i++) {
			if (n - (h * a) - (i * b) >= 0 && (n - (h * a) - (i * b)) % c == 0) {
				ans++;
			}
		}
	}
	cout << ans << endl;
	cin >> n; return 0;
}