hdu1165-Eddy's research II

http://acm.hdu.edu.cn/showproblem.php?pid=1165

#include<iostream>#include<cstdio>#include<cmath>#include<cstring>#include<algorithm>using namespace std ;#define INT __int64INT dfs( INT m , INT n ){    if( n == 0 )        dfs( m - 1 , 1 ) ;    else if( m == 0 )            return n + 2;    else if( m == 1 )            return n + 2 ;    else if( m == 2 )            return 2 * n + 3;    else if( m == 3 )            return dfs( m , n - 1 ) * 2 + 3;}int main(){    INT m , n ;    while( cin >> m >> n )    {        cout << dfs( m , n ) << endl ;    }    return 0;}