The 3n+1 problem （Java代码）

import java.util.Scanner;
   
public class Main {
	    public static void main(String[] args) {
	        Scanner sc=new Scanner(System.in);
	        while (sc.hasNext()) {
	            long a = sc.nextInt();
	            long b = sc.nextInt();
	            System.out.print(a+" "+b+" ");
	            if(a>b){
	            	long t=a;a=b;b=t;
	            }
	            int maxCount=1; 
	            long t=b>>1;
	            for (long i = t>=a?t+1:a; i <=b; i++) {
	            	if((i-1)%3==0){
	            		t=(i-1)/3; if(a<=t&&t<=b)continue;
	            	};
	            	long n=i;
	            	int count=1;
	            	while(n!=1){
					 if(n%2==0) n=n>>1;
	                 else n=n*3+1;
	                 count++;
	            	}
	            	if(count>maxCount) maxCount=count;
				}
	       System.out.println(maxCount);// 输出最大值
	    }
	}
}