import java.util.Scanner; public class Main{ public static void main(String []args){ Scanner sc = new Scanner(System.in); int n = sc.nextInt(); int count = 0; while(true){ if(n % 2 == 0){ n = n / 2; count++; if(n == 1){ break; } }else{ n = n * 3 + 1; count++; if(n % 2 == 0){ n = n / 2; count++; if(n == 1){ break; } } } } System.out.printf("%d",count); } }定义一个count来计算次数,当n偶数时,直接除以2一直到n == 1 时在停止循环,奇数就多一步,先乘3在加1,后面的步骤和偶数一样。