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 <algorithm>
#include <string>
#include <vector>
#define _USE_MATH_DEFINES
#include <math.h>
#include <iomanip>
#include <stdio.h>
#include <numeric>
#include <cmath>
#include <limits>
#include <bitset> 
#include <iterator> 
#include <map>
#include <queue>
#include <set>
#include<deque>
#include <regex>
#include <list> 
#define rep(i,n) for(ll i=0;i<(n); ++i)
#define per(i,n) for(ll i=n-1;i>=0; --i)
#define all(x) (x).begin(),(x).end()
#define _GLIBCXX_DEBUG
using namespace std;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const long long INF = 1LL << 60;
typedef long long ll;
const ll MOD = 1000000007;
ll gcd(ll a, ll b) {
	if (b == 0) return a;
	return gcd(b, a % b);
}
ll getDigit(ll n) {
	ll cnt = 0;
	while (n != 0) {
		n /= 10;
		cnt++;
	}
	return cnt;
}
int main() {
	ll r, g, b, n,cnt = 0;
	cin >> r >> g >> b >> n;
	for (ll i = 0; i <= n; i++){
		for (ll k = 0; k <= n; k++) {
			if (n - (r * i + g * k) < 0)break;
			if ((n - (r * i + g * k)) % b == 0)cnt++;
		}
	}
	cout << cnt << endl;
}