hdu1165 Eddy's research II

就是单纯的递推就能推出来

#include <stdio.h>

long int out ( long int a, long int b ) {
    long long ans;
    if ( b == 0 ) return out ( a - 1, 1 );
    else if ( a == 1 ) return b + 2;
    else if ( a == 2 ) return 2 * b + 3;
    else if ( a == 3 ) return out ( a, b - 1 ) * 2 + 3;                         
}

int main ( ) {
    long int m, n;
    while ( scanf ( "%ld%ld", &m, &n ) != EOF ) {
        printf ( "%ld\n",out ( m, n ) );
    }
}