POJ 3154/模拟(最小墓地移动长度)

Sample Input
sample input #1
2 1

sample input #2
2 3

sample input #3
3 1

sample input #4
10 10

Sample Output
sample output #1
1666.6667

sample output #2
1000.0

sample output #3
1666.6667

sample output #4
0.0

#include "stdio.h"
int main()
{

int before,after;
double be,af,sum=0.0;
scanf("%d%d",&before,&after);
be=(double)10000/before;
af=(double)10000/(before+after);
int j=1;
for(int i=1;i<before;i++)
{

double p1,p2;
p1=i*be;
while(1)
{

p2=j*af;
if(p2<=p1&&p1<=p2+af)break;
j++;
}
if(p1-p2<p2+af-p1)sum+=p1-p2;
else sum+=p2+af-p1;
}
if((int)sum==sum)printf("%d.0",(int)sum);
else
printf("%.4lf",sum);
return 0;
}