做题感悟：比赛时做完第三题就关门了，回去想了一下也没想到好的方法，感觉弱爆了。
解题思路：
官方题解：
代码：
#include<iostream>
#include<sstream>
#include<map>
#include<cmath>
#include<fstream>
#include<queue>
#include<vector>
#include<sstream>
#include<cstring>
#include<cstdio>
#include<stack>
#include<bitset>
#include<ctime>
#include<string>
#include<iomanip>
#include<algorithm>
using namespace std ;
#define INT long long int
const int INF = 99999999 ;
const double esp = 0.00000001 ;
const double PI = acos(-1.0) ;
const int MP = 2000000 + 5 ;
const int MY = (1<<9) + 5 ;
const int MX = 100000 + 5 ;
int n ,a ,b ;
map<int ,int>m ;
int g[MX] ,fa[MX] ;
int find(int x)
{
if(fa[x] != x)
fa[x] = find(fa[x]) ;
return fa[x] ;
}
int main()
{
while(~scanf("%d%d%d" ,&n ,&a ,&b))
{
m.clear() ;
for(int i = 1 ;i <= n ; ++i)
{
scanf("%d" ,&g[i]) ;
m[g[i]] = i ;
}
for(int i = 1 ;i <= n+2 ; ++i)
fa[i] = i ;
for(int i = 1 ;i <= n ; ++i)
{
if(m[a-g[i]])
fa[find(i)] = find(m[a-g[i]]) ;
else fa[find(i)] = find(n+2) ;
if(m[b-g[i]])
fa[find(i)] = find(m[b-g[i]]) ;
else fa[find(i)] = find(n+1) ;
}
if(find(n+1) == find(n+2))
cout<<"NO"<<endl ;
else
{
cout<<"YES"<<endl ;
for(int i = 1 ;i <= n ; ++i)
{
if(i != 1) cout<<" " ;
cout<<(find(i) == find(n+2)) ;
}
cout<<endl ;
}
}
return 0 ;
}