BZOJ 2048 题解

/**************************************************************
    Problem: 2048
    User: shadowland
    Language: C++
    Result: Accepted
    Time:0 ms
    Memory:1300 kb
****************************************************************/
 
#include "bits/stdc++.h"
 
using namespace std ;
typedef long long QAQ ;
typedef double db ;
const db Euler_const = 0.5772156649015328606065120900824024310421593359 ; 
const db eps = 1e-10 ;
 
int main ( ) {
        db tmp = 0.0000 , N , M ;
        cin >> N >> M ; 
        if ( N <= 1e4 ) for ( int i=1 ; i<=N ; ++i ) tmp += ( 1.000 / ( db ) i ) ;
        else tmp = log ( N + 1.000 ) + Euler_const ; 
        tmp *= ( M * 0.500 ) ;
        cout << ( QAQ ) ceil ( tmp - 1 ) << endl ;
        return 0 ;  
}