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【Java】【找規律】Gym - 101243B - Hanoi tower

開始 輸出 red port n-1 mat brush 規律 讀寫

題意:給你一個經典的漢諾塔遞歸程序,問你最少幾步使得三個柱子上的盤子數量相同。(保證最開始盤子數量可以被3整除)

規律:ans(n)=2^(2*n/3-1)+t(n/3)。

t(1)=0.

t(n)=

t(n-1)+1,n為偶數

t(n-1)*4+2,n為奇數。

Java文件讀寫主要有以下兩種方法,第二種,輸出格式更隨心所欲,更實用:

import java.util.*;
import java.io.*;
import java.math.*;

public class Main{
	public static void main(String[] argc){
		BigInteger[] t=new BigInteger[305];
		BigInteger[] pw=new BigInteger[305];
		t[1]=BigInteger.ZERO;
		for(int i=2;i<=100;++i){
			if(i%2==0){
				t[i]=t[i-1].add(BigInteger.ONE);
			}
			else{
				t[i]=t[i-1].multiply(BigInteger.valueOf(4l)).add(BigInteger.valueOf(2l));
			}
		}
		pw[0]=BigInteger.ONE;
		for(int i=1;i<=300;++i){
			pw[i]=pw[i-1].multiply(BigInteger.valueOf(2l));
		}
		Scanner cin = new Scanner(System.in);
		try{cin=new Scanner(new FileInputStream("input.txt"));}catch(Exception e){}
		int n=cin.nextInt();
		cin.close();
		/*pw[2*n/3-1].add(t[n/3]).toString()*/
		File file=new File("output.txt");
		try{
			BufferedWriter bf=new BufferedWriter(new PrintWriter(file));
			bf.append(pw[2*n/3-1].add(t[n/3]).toString());
			bf.close();
		}
		catch(Exception e){}
    }
}
import java.util.*;
import java.io.*;
import java.math.*;

public class Main{
	public static void main(String[] argc){
		BigInteger[] t=new BigInteger[305];
		BigInteger[] pw=new BigInteger[305];
		t[1]=BigInteger.ZERO;
		for(int i=2;i<=100;++i){
			if(i%2==0){
				t[i]=t[i-1].add(BigInteger.ONE);
			}
			else{
				t[i]=t[i-1].multiply(BigInteger.valueOf(4l)).add(BigInteger.valueOf(2l));
			}
		}
		pw[0]=BigInteger.ONE;
		for(int i=1;i<=300;++i){
			pw[i]=pw[i-1].multiply(BigInteger.valueOf(2l));
		}
		Scanner cin = new Scanner(System.in);
		try{cin=new Scanner(new FileInputStream("input.txt"));}catch(Exception e){}
		int n=cin.nextInt();
		cin.close();
		/*pw[2*n/3-1].add(t[n/3]).toString()*/
		//File file=new File("output.txt");
		try{
			FileWriter fw = new FileWriter("output.txt", true);
			PrintWriter cout = new PrintWriter(fw);
			cout.println(pw[2*n/3-1].add(t[n/3]));
			cout.flush();
			//BufferedWriter bf=new BufferedWriter(new PrintWriter(file));
			//bf.append(pw[2*n/3-1].add(t[n/3]).toString());
			//bf.close();
		}
		catch(Exception e){}
    }
}

【Java】【找規律】Gym - 101243B - Hanoi tower