Biorhythms 需要数学推导

#include <stdio.h>
#include <stdlib.h>

double pi = 3.1415926535898;
int main(int argc, char *argv[])
{
	int p, e, i, d;
	int k1, k2, k3;
	int days;
	int cnt = 1;

	while (true)
	{
		scanf("%d %d %d %d", &p, &e, &i, &d);
		if (p==-1 && e==-1 && i==-1 && d==-1)
			break;
		
		p = p % 23;
		e = e % 28;
		i = i % 33;

		k1 = k2 = k3 = 0;	 
		days = (5544 * p + 14421 * e + 1288 * i - d) % (21252);      
		if (days <= 0) {             
			days = 23 * 28 * 33 + days;       
		} 
		printf("Case %d: the next triple peak occurs in %d days.\n", cnt++, days);	
	}
	return 0;
}