C++高精度问题太蛋疼了....
Yukari's Birthday
Time Limit: 12000/6000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 2891 Accepted Submission(s): 604
Problem Description
Today is Yukari's n-th birthday. Ran and Chen hold a celebration party for her. Now comes the most important part, birthday cake! But it's a big challenge for them to place n candles on the top of the cake. As Yukari has lived for such a long long time, though she herself insists that she is a 17-year-old girl.
To make the birthday cake look more beautiful, Ran and Chen decide to place them like r ≥ 1 concentric circles. They place k
i candles equidistantly on the i-th circle, where k ≥ 2, 1 ≤ i ≤ r. And it's optional to place at most one candle at the center of the cake. In case that there are a lot of different pairs of r and k satisfying these restrictions, they want to minimize r × k. If there is still a tie, minimize r.
Input
There are about 10,000 test cases. Process to the end of file.
Each test consists of only an integer 18 ≤ n ≤ 10
12.
Output
For each test case, output r and k.
Sample Input
Sample Output
Source
2012 Asia ChangChun Regional Contest
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
using namespace std;
typedef long long int LL;
LL n;
LL check(LL r)
{
LL low=2,high=n,mid,ret=-1;
while(low<=high)
{
mid=(low+high)/2;
if(((LL)(pow(mid*1.,r-1.))>n||(LL)(pow(mid*1.,r-1.))<0)
||(LL)(pow(mid*1.,r*1.))>n||(LL)(pow(mid*1.,r*1.))<0)
{
high=mid-1;
continue;
}
LL temp=mid*(1-(LL)(pow(mid*1.,r*1.)))/(1-mid);
if(temp<=n-1||temp<=n)
{
if(temp==n||temp==n-1) ret=mid;
low=mid+1;
}
else
{
high=mid-1;
}
}
return ret;
}
int main()
{
while(scanf("%I64d",&n)!=EOF)
{
LL R=1,K=n-1,ans=(1LL<<60);
for(LL r=2;r<40;r++)
{
LL k=check(r);
if(k==-1) continue;
if(ans>r*k)
{
R=r; K=k;
}
}
printf("%I64d %I64d\n",R,K);
}
return 0;
}