四川oi 萌萌哒 （分层并查集）

#include <bits/stdc++.h>
#define inf 0x3f3f3f3f
#define met(a,b) memset(a,b,sizeof a)
#define pb push_back
#define mp make_pair
#define inf 0x3f3f3f3f
using namespace std;
typedef long long ll;
const int N = 1e6+5500;;
const int M = 160009;
const int mod = 1e9+7;
const double pi= acos(-1.0);
typedef pair<int,int>pii;
int n,m,T;
int up[N],go[N],fa[20][N];
int findfa(int k,int x){
    return x==fa[k][x]?x:fa[k][x]=findfa(k,fa[k][x]);
}
void unionfa(int k,int x,int y){
    int X = x,Y = y;
    x=findfa(k,x);
    y=findfa(k,y);
    if(x==y)return;
    fa[k][x]=y;
    if(!k)return;
    unionfa(k-1,X,Y);
    unionfa(k-1,X+(1<<k-1),Y+(1<<k-1));
}
int main(){
    scanf("%d%d",&n,&m);
    for(int j=0;j<20;j++)for(int i=0;i<N;i++)fa[j][i]=i;
    for(int i=0,l1,r1,l2,r2;i<m;i++){
        scanf("%d%d%d%d",&l1,&r1,&l2,&r2);
        if(l1>l2){
            swap(l1,l2);swap(r1,r2);
        }
        int k=log2(r1-l1+1);
        unionfa(k,l1,l2);unionfa(k,r1-(1<<k)+1,r2-(1<<k)+1);
    }
    int cnt=0;
    ll ans=9;
    for(int i=1;i<=n;i++){
        if(findfa(0,i)==i)cnt++;
    }
    for(int i=0;i<cnt-1;i++){
        ans=ans*10%mod;
    }
    if(n==1)puts("10");
    else printf("%lld\n",ans);
    return 0;
}