ICPC Pacific Northwest Regional Contest 2019

 D. Dividing by Two

 

题意：偶数除二，奇数加一，直到两数相等，需要多少次

ac代码：

#include<iostream> 
using namespace std;
#define ll long long 
int main(){
	ll a,b,sum=0;
	cin>>a>>b;
while(a!=b)	{
if(a<b){
	a=a+1;
	sum++;	
	}
	else{
		if(a%2==0){
			a/=2;
			sum++;
		}
		else{
			a+=1;
			sum++;
		}
	}
	}
	cout<<sum<<endl;
}