递归练习
1 import java.io.IOException; 2 3 public class Digui1 { 4 5 public static void main(String[] args) { 6 // TODO Auto-generated method stub 7 Digui1 d= new Digui1(); 8 try { 9 d.printInput(); 10 } catch (IOException e) { 11 e.printStackTrace(); 12 } 13 } 14 15 private void printInput() throws IOException { 16 char i = (char) System.in.read(); 17 if (i != '#') { 18 printInput(); 19 } 20 if (i != '#') { 21 System.out.print(i); 22 } 23 } 24 25 }
1 import java.io.IOException; 2 3 public class Digui1 { 4 5 int a[] = {1,1,2,3,5,8,13,21,34,55,88}; 6 int low = 0; 7 int high = 10; 8 int mid = (low+high)/2; 9 public static void main(String[] args) { 10 Digui1 d= new Digui1(); 11 d.search(34); 12 } 13 14 private void search(int key) { 15 16 if(a[mid] < key) { 17 low = mid+1; 18 mid = (low+high)/2; 19 search(key); 20 } 21 else if(a[mid] > key) { 22 high = mid-1; 23 mid = (low+high)/2; 24 search(key); 25 } 26 else{ 27 System.out.print(mid); 28 } 29 } 30 }
折半查找法：输出8
汉诺塔问题：
1 public class Digui1 { 2 static int step; 3 static int p; 4 public static void main(String[] args) { 5 Digui1 d= new Digui1(); 6 d.move(4,'x','y','z'); 7 System.out.println("step:"+step); 8 System.out.println(p); 9 } 10 //将n个盘子借助y从x移到z 11 private void move(int n,char x,char y, char z) { 12 p++; 13 if(n == 1) { 14 System.out.println(x+"→"+z); 15 step++; 16 }else{ 17 move(n-1,x,z,y);//将n-1个盘子借助z从x移到y 18 System.out.println(x+"→"+z); 19 step++; 20 move(n-1,y,x,z);//将n-1个盘子借助x从y移到z 21 } 22 } 23 }
1 x→y 2 x→z 3 y→z 4 x→y 5 z→x 6 z→y 7 x→y 8 x→z 9 y→z 10 y→x 11 z→x 12 y→z 13 x→y 14 x→z 15 y→z 16 step:15 17 15
目标：将n个盘子从x借助y移动到z
步骤：
1、将n-1个盘子从x借助z移动到y；
2、将第n个盘子从x移动到z上
3、将n-1个盘子从y借助x移动到z。
