8/9，集合的运算

就是暴力的四种方法都算出答案，然后进行比较有没有这个答案就好了

#include<bits/stdc++.h>
#define sf scanf
#define scf(x) scanf("%d",&x)
#define scff(x,y) scanf("%d%d",&x,&y)
#define scfff(x,y,z) scanf("%d%d%d",&x,&y,&z)
#define pf printf
#define prf(x) printf("%d
",x)
#define mm(x,b) memset((x),(b),sizeof(x))
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=a;i>=n;i--)
#define pb push_back
typedef long long ll;void read(int &x){
int f=1;x=0;char s=getchar();
while(s<'0'||s>'9'){if(s=='-')f=-1;s=getchar();}
while(s>='0'&&s<='9'){x=x*10+s-'0';s=getchar();}
x*=f;}
const ll mod=1e9+100;
const double eps=1e-8;
using namespace std;
const double pi=acos(-1.0);
const int inf=0xfffffff;
const int N=1005;
vector<int> v[3];
vector<int> vv[3];
vector<int> ans[4];
int main()
{
	int x,n,m,k;
	scfff(n,m,k);
	rep(i,0,n)
	{
		scf(x);
		v[0].pb(x);
	}
	rep(i,0,m)
	{
		scf(x);
		v[1].pb(x);
	}
	rep(i,0,k)
	{
		scf(x);
		v[2].pb(x);
	}
	sort(v[0].begin(),v[0].end());
	sort(v[1].begin(),v[1].end());
	sort(v[2].begin(),v[2].end());
	vv[0].pb(v[0][0]);
	vv[1].pb(v[1][0]);
	vv[2].pb(v[2][0]);
	rep(j,0,3)
	rep(i,1,v[j].size())
	{
		if(v[j][i]!=v[j][i-1])
			vv[j].pb(v[j][i]);
	}
	n=vv[0].size();
	m=vv[1].size();
	k=vv[2].size();
	int pos1=0,pos2=0;
	while(1)//进行并集和交集的
	{
		if(pos1==n&&pos2==m)break;
		if(pos1==n)
			ans[0].pb(vv[1][pos2++]);
		else if(pos2==m)
			ans[0].pb(vv[0][pos1++]);
		else 
		{
			if(vv[0][pos1]>vv[1][pos2])
			{
				ans[0].pb(vv[1][pos2++]);
			}else if(vv[0][pos1]<vv[1][pos2])
			{
				ans[0].pb(vv[0][pos1++]);
			}else
			{
				ans[0].pb(vv[0][pos1]);
				ans[1].pb(vv[0][pos1]);
				pos1++;
				pos2++;
			}
		}
	}
	pos1=0;pos2=0;
	while(1)//进行1减2
	{
		if(pos1==n)
			break;
		else if(pos2==m)
			ans[2].pb(vv[0][pos1++]);
		else 
		{
			if(vv[0][pos1]>vv[1][pos2])
			{
				pos2++;
			}else if(vv[0][pos1]<vv[1][pos2])
			{
				ans[2].pb(vv[0][pos1++]);
			}else
			{
				pos1++;
				pos2++;
			}
		}
	}
	pos1=0;pos2=0;
	while(1)//进行2减1
	{
		if(pos2==m)
			break;
		else if(pos1==n)
			ans[3].pb(vv[1][pos2++]);
		else 
		{
			if(vv[0][pos1]>vv[1][pos2])
			{
				ans[3].pb(vv[1][pos2++]);
				
			}else if(vv[0][pos1]<vv[1][pos2])
			{
				pos1++;
			}else
			{
				pos1++;
				pos2++;
			}
		}
	}
	rep(i,0,4)//比较四种答案
	{
		if(ans[i].size()==vv[2].size())
		{
			int temp=1;
			rep(j,0,ans[i].size())
			{
				if(ans[i][j]!=vv[2][j])
				{
					temp=0;
					break;
				}
			}
			if(temp)
			{
				rep(j,0,vv[2].size())
				{
					if(j==0)
					pf("%d",vv[2][j]);
					else
					pf(" %d",vv[2][j]);
				}
				return 0;
			}
		}
	}
	pf("What a pity!");
	return 0;
}