CF1325D-分类讨论，找规律

CF1325D

题目描述

题解

大力分类讨论，详见下方代码

代码

#include<bits/stdc++.h>
#define int long long
using namespace std;
int read(){
	int f=1,re=0;char ch;
	for(ch=getchar();!isdigit(ch)&&ch!='-';ch=getchar());
	if(ch=='-'){f=-1,ch=getchar();}
	for(;isdigit(ch);ch=getchar()) re=(re<<3)+(re<<1)+ch-'0';
	return re*f;
}
int n,m,bj,ans,vis[70];
signed main(){
	n=read(),m=read();
	if(!n&&!m){
		printf("0\n");
		return 0;
	}
	if(n>m){
		printf("-1\n");
		return 0;
	}
	if(n==m){
		printf("1\n");
		printf("%lld\n",n);
		return 0;
	}m=m-n;
	if(m%2==1ll){
		printf("-1\n");
		return 0;
	}
	if(m%2==0ll){
		for(int i=0;i<=62;i++){
			if(n&(1ll<<i)) continue;
			vis[i+1]=1;
		}
		for(int i=0;i<=62;i++){
			if(m&(1ll<<i)&&!vis[i]){bj=1;break;}
			if(m&(1ll<<i)&&vis[i]) vis[i]=2;
		}
		if(bj){
			printf("3\n");
			printf("%lld %lld %lld\n",m/2,m/2,n);
		}
		else{
			printf("2\n");
			for(int i=0;i<=62;i++)
				if(vis[i]==2) ans+=(1ll<<(i-1ll)),n+=(1ll<<(i-1ll));
			printf("%lld %lld",ans,n);
		}
	}return 0;
}