翻转+交换

Posted 2022-12-15 混个样子出来

翻转

两种方法

import java.util.Scanner;

public class Main 
	public static void main(String[] args) 
		Scanner sc = new Scanner(System.in);
		while(sc.hasNext()) 
			int n=sc.nextInt();//翻转的整数
			int sum=0;
			while(n>0) 
				//System.out.print(n%10);//可看每一次的值
				sum=sum*10+n%10;//sum扩大10倍+加一次得到的尾数
				n/=10;
			
			System.out.println(sum);
		
	

import java.util.Scanner;

public class Main 
	public static void main(String[] args) 
		Scanner sc = new Scanner(System.in);
		while(sc.hasNext()) 
			int n=sc.nextInt();
			System.out.println(new StringBuffer(String.valueOf(n)).reverse().toString());
			
		
	

交换两个数（除了引入中间变量）

方法一：

int a=3;

int b=6;

a=a+b;//12

b=a-b;//3

a=a-b;//9

方法二（采用异或）：

import java.util.Scanner;

public class Main 
	public static void main(String[] args) 
		Scanner sc = new Scanner(System.in);
		while(sc.hasNext()) 
			int a=sc.nextInt();
			int b=sc.nextInt();
			a=a^b;
			b=a^b;
			a=a^b;
			System.out.println("a="+a+",b="+b);