#include<stdio.h>int main(){ int a; int b=0; scanf("%d",&a); while(a!=1) { if(a%2==1) { a=3*a+1; }else { a=a/2; } b++; } printf("%d\n",b%3); } return 0;}
3n+1
原文:https://www.cnblogs.com/lijianmin6/p/10185391.html