代码如下：

#include<bits/stdc++.h>

using i8=char;		using u8=unsigned char;
using i16=short;	using u16=unsigned short;
using i32=int;		using u32=unsigned int;
using i64=long long;using u64=unsigned long long;
using i128=__int128;using u128=unsigned __int128;
using f32=float; 	using f64=double;				using f128=long double;

template<typename T> inline void read(T &x){
	char ch=getchar(),f=0;
	x=0;
	while(ch<'0'||ch>'9')f|=(ch=='-'),ch=getchar();
	while(ch>='0'&&ch<='9')(x=x*10+(ch-'0')),ch=getchar();
	x=(f?-x:x);
}
template<typename T,typename ...Ts> void read(T &x,Ts &...xs){read(x); read(xs...); }
char fostk[50]; u8 cntfostk;
template<typename T> inline void write(T x){
	if(x<0)putchar('-'),x=-x;
	while(x>9)fostk[++cntfostk]='0'+x%10,x/=10;
	fostk[++cntfostk]=x+'0';
	while(cntfostk)putchar(fostk[cntfostk--]);
}
template<typename T> void writesp(T x){write(x); putchar(' '); }
template<typename T> void writeln(T x){write(x); putchar('\n'); }
template<typename T> void writelns(T x){writeln(x); }
template<typename T,typename ...Ts> void write(T x,Ts ...xs){writesp(x); write(xs...); }
template<typename T,typename ...Ts> void writeln(T x,Ts ...xs){write(x,xs...); putchar('\n'); }
template<typename T,typename ...Ts> void writelns(T x,Ts ...xs){writeln(x); writelns(xs...); }
constexpr i32 dx[]={-1,-1,-1,0,0,1,1,1}, dy[]={-1,0,1,-1,1,-1,0,1};
i32 n,r,c;
struct Node{
	i32 bel,dfn,low;
	bool ins,tag;
	static i32 cntdfn;
}nod[12000050];
struct Point{
	i32 x,y,t;
}pt[10000050];
struct Scc{
	i32 size,vis,dp;
	static i32 cntscc;
}scc[12000050];
i32 Node::cntdfn=0,Scc::cntscc=0;
i32 rp(i32 x){return n+x; }
i32 cp(i32 x){return n+r+x; }
std::basic_string<i32> G[1200005],DAG[1200005];
std::map<std::tuple<i32,i32>,i32> mp;
std::stack<i32> s;
void tarjan(i32 x){
	nod[x].dfn=++Node::cntdfn;
	nod[x].low=nod[x].dfn;
	nod[x].ins=true;
	s.push(x);
	for(auto v:G[x]){
		if(!nod[v].dfn){
			tarjan(v);
			nod[x].low=std::min(nod[x].low,nod[v].low);
		}else if(nod[v].ins)nod[x].low=std::min(nod[x].low,nod[v].low);
	}
	if(nod[x].low==nod[x].dfn){
		i32 now=++Scc::cntscc,y;
		do{
			y=s.top();
			s.pop();
			scc[now].size+=nod[y].tag;
			nod[y].bel=now;
			nod[y].ins=false;
		}while(x!=y);
	}
}
i32 dfs(i32 x){
	if(scc[x].vis)return scc[x].dp;
	scc[x].vis=true;
	i32 re=scc[x].size,big=0;;
	for(auto v:DAG[x]){
		big=std::max(big,dfs(v));
	}
	return scc[x].dp=re+big;
}
i32 main(){
#ifdef LOCAL
	freopen("test.in","r",stdin);
	freopen("test.out","w",stdout);
	freopen("test.err","w",stderr);
#endif
	read(n,r,c);
	for(i32 i=1;i<=n;i++){
		read(pt[i].x,pt[i].y,pt[i].t);
		nod[i].tag=1;
		mp[std::make_tuple(pt[i].x,pt[i].y)]=i;
	}
	for(i32 i=1;i<=n;i++){
		G[rp(pt[i].x)]+=i;
		G[cp(pt[i].y)]+=i;
		if(pt[i].t==1){
			G[i]+=rp(pt[i].x);
		}else if(pt[i].t==2){
			G[i]+=cp(pt[i].y);
		}else{
			for(i32 j=0;j<8;j++){
				auto tmp=std::make_tuple(pt[i].x+dx[j],pt[i].y+dy[j]);
				if(mp.find(tmp)!=mp.end()){
					G[i]+=mp[tmp];
					// printf("tmp.x:%d tmp.y:%d\n",)
				}
			}
		}
	}
	for(i32 i=1;i<=n+r+c;i++){
		if(!nod[i].dfn)tarjan(i);
	}
	for(i32 i=1;i<=n+r+c;i++){
		for(auto v:G[i]){
			if(nod[v].bel==nod[i].bel)continue;
			DAG[nod[i].bel]+=nod[v].bel;
		}
	}
	// for(i32 i=1;i<=Scc::cntscc;i++){
	// 	for(auto v:DAG[i]){
	// 		// printf("i:%d scc[i].size:%d v:%d scc[i].size:%d\n",i,scc[i].size,v,scc[v].size);
	// 	}
	// }
	i32 ans=0;
	// for(i32 i=1;i<=n+r+c;i++){
	// 	for(auto v:G[i]){
	// 		printf("i:%d v:%d bel[i]:%d bel[v]:%d\n",i,v,nod[i].bel,nod[v].bel);
	// 	}
	// }
	// printf("Scc::cntscc:%d\n",Scc::cntscc);
	for(i32 i=1;i<=Scc::cntscc;i++){
		// printf("scc[i:%d].size:%d\n",i,scc[i].size);
		if(!scc[i].vis)ans=std::max(ans,dfs(i));
	}
	write(ans);
	return 0;
}

帮帮蒟蒻吧