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: Wrong Answer)

#include <iostream> // cin, cout, cerr, clog
#include <algorithm> // minmax, sort, swap
#include <numeric> // iota, gcd, lcm 
#include <cstdio> // printf, scanf
#include <climits> // INT_MIN, LLONG_MIN
#include <cmath> // long, trig, pow
#include <vector> // vectors
#include <string> // string
#include <queue> // queue
#include <stack> // stack
#include <map> // key-value pairs sorted by keys
#include <unordered_map> // hashed by keys
#define _for(i,n) for(int i = 0; i <= n; i++)

typedef long long ll; // at least int64 > 9*10^18
typedef unsigned long long ull; // at least uint64

using namespace std;

int main() {
  int R,G,B,n;
  cin >> R >> G >> B >> n;
  int rmax = n/R;
  int gmax = n/G;
  int bmax = n/B;
  int count = 0;
  _for(r,rmax) _for(g,gmax-r*R/G) if ((n-r*R+g*G)%B) count++;
  cout << count << endl;
  return 0;
}