Submission #1470084

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Source Code Expand

// This amazing code is by Eric Sunli Chen.
#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <utility>
#include <vector>
using namespace std;
template<typename T> void get_int(T &x)
{
	char t=getchar();
	bool neg=false;
	x=0;
	for(; (t>'9'||t<'0')&&t!='-'; t=getchar());
	if(t=='-')neg=true,t=getchar();
	for(; t<='9'&&t>='0'; t=getchar())x=x*10+t-'0';
	if(neg)x=-x;
}
template<typename T> void print_int(T x)
{
	if(x<0)putchar('-'),x=-x;
	short a[20]= {},sz=0;
	while(x>0)a[sz++]=x%10,x/=10;
	if(sz==0)putchar('0');
	for(int i=sz-1; i>=0; i--)putchar('0'+a[i]);
}
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define get1(a) get_int(a)
#define get2(a,b) get1(a),get1(b)
#define get3(a,b,c) get1(a),get2(b,c)
#define printendl(a) print_int(a),puts("")
typedef long long LL;
typedef unsigned long long uLL;
typedef pair<int,int> pii;
const int inf=0x3f3f3f3f;
const LL Linf=1ll<<61;
const double pi=acos(-1.0);

const int mod=1e9+7;

int power(int x,int y)
{
	int ret=1;
	while(y)
	{
		if(y&1)ret=1ll*ret*x%mod;
		x=1ll*x*x%mod;
		y>>=1;
	}
	return ret;
}
int n,x,y,c[200111],w[200111];
vector<pii> v[200111];
map<int,int> cnt[200111];
int sz[200111],f[200111],fac[200111],invf[200111];
int gf(int x){return x==f[x]?x:f[x]=gf(f[x]);}
void un(int x,int y)
{
	x=gf(x);y=gf(y);
	if(x==y)return;
	if(sz[x]<sz[y])swap(x,y);
	f[y]=x;
	sz[x]+=sz[y];
}
int main()
{
	fac[0]=invf[0]=1;
	for(int i=1;i<200111;i++)
	{
		fac[i]=1ll*fac[i-1]*i%mod;
		invf[i]=power(fac[i],mod-2);
	}
	
	get3(n,x,y);
	for(int i=1;i<=n;i++)
	{
		f[i]=i;sz[i]=1;
		get2(c[i],w[i]);
		v[c[i]].pb(mp(w[i],i));
	}
	int mn=0,mn2=0;
	for(int i=1;i<=n;i++)
	{
		if((int)v[i].size()==0)continue;
		sort(v[i].begin(),v[i].end());
		for(int j=1;j<(int)v[i].size();j++)
		{
			if(v[i][0].ff+v[i][j].ff<=x)
				un(v[i][0].ss,v[i][j].ss);
		}
		if(mn==0||v[mn][0].ff>v[i][0].ff)
		{
			mn2=mn;
			mn=i;
		}
		else if(mn2==0||v[mn2][0].ff>v[i][0].ff)mn2=i;
	}
	if(mn)mn=v[mn][0].ss;if(mn2)mn2=v[mn2][0].ss;
	for(int i=1;i<=n;i++)
	{
		if(c[i]!=c[mn]&&w[i]+w[mn]<=y)un(i,mn);
		else if(c[i]!=c[mn2]&&w[i]+w[mn2]<=y)un(i,mn2);
	}
	for(int i=1;i<=n;i++)cnt[gf(i)][c[i]]++;
	int ans=1,sum=0;
	for(int i=1;i<=n;i++)if(f[i]==i)
	{
		sum+=sz[i];
		ans=1ll*ans*fac[sz[i]]%mod;
		for(map<int,int>::iterator it=cnt[i].begin();it!=cnt[i].end();it++)
			ans=1ll*ans*invf[it->ss]%mod;
	}
	printendl(ans);
	return 0;
}

Submission Info

Judge Result