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 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>

#define GYOU_MAX 256


int main(void)
{
	int R, G, B, N;
	scanf("%d%d%d%d", &R, &G, &B, &N);

	int count = 0;
	double x;
	for (int i = 0;;i++) {
		if (R*i > N) {
			break;
		}

		for (int j = 0;;j++) {

			x=(double)(N-( R * i + G * j))/B;

			//printf("%d %d %f\n", i, j, x);
			if ((ceil(x) == floor(x))&&x >= 0) {
				count++;
				//printf("[%d %d %d]\n", i, j,(int) x);
			}
			if (R*i + G * j > N) {
				break;
			}
		}
	}

	printf("%d\n", count);

	return 0;
}