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 Ruby (2.3.3) (judge verdict: Runtime Error)

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<int,int> P;
const ll LINF = 1e18;

template <class T>ostream &operator<<(ostream &o,const vector<T>&v)
{o<<"[";for(int i=0;i<(int)v.size();i++)o<<(i>0?", ":"")<<v[i];o<<"]";return o;}
template <class T, class U>ostream &operator<<(ostream &o, const pair<T, U>&p)
{o<<"{"<<p.first<<", "<<p.second<<"}";return o;}
template <class T, class U>ostream &operator<<(ostream &o, const map<T, U>&obj)
{o<<"{";for(auto itr=obj.begin();itr!=obj.end();++itr)o<<(itr!=obj.begin()?", ":"")<<*itr;o<<"}";return o;}

int main()
{
  int r,g,b,n;
  cin >> r >> g >> b >> n;
  vector<int> cnt(n+1,0);

  for(int i=0;i<=n/r;i++){
    for(int j=0;j<=n/g;j++){
      if(i*r+j*g <= n) cnt[i*r+j*g]++;
    }
  }
  int ans = 0;
  for(int i=0;i<=n/b;i++){
    if(i*b<=n) ans += cnt[n-i*b];
  }
  cout << ans << endl;
  return 0;
}