poj2661 Factstone Benchmark（大数不等式同取对数ji）

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<string>
#include<cmath>
#include<map>
#include<set>
#include<list>
#include<deque>
#include<vector>
#include<algorithm>
#include<stack>
#include<queue>
#include<cctype>
#include<sstream>
using namespace std;
#define pii pair<int,int>
#define LL long long int
const double eps=1e-10;
const int INF=1000000000;
const int maxn=0;

int n;

int main()
{
    //freopen("in2.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    while(scanf("%d",&n)==1&&n)
    {
        int t=(n-1960)/10+2;
        int k=(1<<t);
        //cout<<k<<endl;
        double i=1;
        double r=0;
        for(;r<(double)k;i++)
        {
            //cout<<‘i‘<<‘ ‘<<i<<endl;
            //cout<<log(i)/log(2)<<endl;
            r+=log(i)/log(2.0);
            //cout<<r<<endl;
        }
        cout<<i-2<<endl;
    }
    //fclose(stdin);
    //fclose(stdout);
    return 0;
}