2017ICPC/广西邀请赛1001（水）HDU6181

A Math Problem

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 817    Accepted Submission(s): 344

Problem Description

You are given a positive integer n, please count how many positive integers k satisfy kk≤n

.

 

Input

There are no more than 50 test cases.

Each case only contains a positivse integer n in a line.

1≤n≤1018

 

Output

For each test case, output an integer indicates the number of positive integers k satisfy kk≤n

in a line.

 

Sample Input

1
4

 

Sample Output

1
2

题意

解析  数据会爆longlong 自己快速幂找到爆点 16爆了

 #include <stdio.h>
 #include <math.h>
 #include <string.h>
 #include <stdlib.h>
 #include <iostream>
 #include <sstream>
 #include <algorithm>
 #include <string>
 #include <queue>
 #include <vector>
 using namespace std;
 const int maxn= ;
 const int inf = 0x3f3f3f3f;
 typedef long long ll;
 ll n;
 ll pow1(ll a,ll b)
 {
   ll r=,base=a;
   while(b)
   {
     if(b&) r*=base;
     base*=base;
     b>>=;
   }
   return r;
 }
 int main(int argc, char const *argv[])
 {
     while(scanf("%lld",&n)==)
     {
         for(int i=;i>=;i--)
         {
             if(pow1(i,i)<=n)
             {
                 cout<<i<<endl;
                 break;
             }

         }
     }
     return ;
 }