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>
#include <algorithm>
#include <math.h> 
#include <string>
#include <iomanip>
#include <vector>
using namespace std;
int main(){
    int r, g, b, n;
    cin >> r >> g >> b >> n;
    int ans = 0;
    for(int i = 0; i <= 3000; i++){
        for(int j = 0; j <= 3000; j++){
            int k = (n - i*r + j*g)/b;
            if(k >= 0) ans++;
        }
    }
    cout << ans << endl;
}