HDU1592-Half of and a Half

Half of and a Half

                                                                             Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
                                                                                                        Total Submission(s): 1183    Accepted Submission(s): 540

Problem Description

Gardon bought many many chocolates from the A Chocolate Market (ACM). When he was on the way to meet Angel, he met Speakless by accident. 
"Ah, so many delicious chocolates! I'll get half of them and a half!" Speakless said.
Gardon went on his way, but soon he met YZG1984 by accident....
"Ah, so many delicious chocolates! I'll get half of them and a half!" YZG1984 said.
Gardon went on his way, but soon he met Doramon by accident....
"Ah, so many delicious chocolates! I'll get half of them and a half!" Doramon said.
Gardon went on his way, but soon he met JGShining by accident....
"Ah, so many delicious chocolates! I'll get half of them and a half!" JGShining said.
.
.
.
After had had met N people , Gardon finally met Angel. He gave her half of the rest and a half, then Gardon have none for himself. Could you tell how many chocolates did he bought from ACM?  

Input

Input contains many test cases.
Each case have a integer N, represents the number of people Gardon met except Angel. N will never exceed 1000;  

Output

For every N inputed, tell how many chocolates Gardon had at first.  

Sample Input

  

   2
    
  

Sample Output

  

   7
  

Author

DYGG  

Source

HDU “Valentines Day” Open Programming Contest 2007-02-14

 

题意：题意是见一个人分总数的一半+0.5，最后正好没有，问总共有多少

import java.math.BigInteger;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		BigInteger bigInteger=BigInteger.ONE;
		while(scanner.hasNext()){
			int n;
			n=scanner.nextInt();
			for(int i=0;i<n;i++){
				bigInteger=bigInteger.multiply(BigInteger.valueOf(2));
				bigInteger=bigInteger.add(BigInteger.ONE);
			}
			System.out.println(bigInteger);
			bigInteger=BigInteger.ONE;
		}
		scanner.close();
	}
}