Submission #908966

#	Time	Username	Problem	Language	Result	Execution time	Memory
908966		089487	Regions (IOI09_regions)	C++14	95 / 100	7142 ms	131072 KiB

regions

#include<bits/stdc++.h>
//#define int long long
#define quick ios::sync_with_stdio(0);cin.tie(0);
#define rep(x,a,b) for(int x=a;x<=b;x++)
#define repd(x,a,b) for(int x=a;x>=b;x--)
#define lowbit(x) (x&-x)
#define F first
#define S second
#define sz(x) (int)(x.size())
#define all(x) x.begin(),x.end()
#define mp make_pair
#define eb emplace_back
using namespace std;
typedef pair<int,int> pii;
void debug(){
    cout<<"\n";
}
template <class T,class ... U >
void debug(T a, U ... b){
    cout<<a<<" ",debug(b...);
}
const int N=4e5+2;
const int INF=1e18;
const int K=500;
const int K2=400;
vector<int> cnt[N];
int pnt[K2][N];
int chd[K2][N];
int idx[N];
int c[N];
vector<int> v[N];
int in[N],out[N];
int t=1;
void dfs(int x){
    in[x]=t++;
    for(int i:v[x]){
        dfs(i);
    }
    out[x]=t++;
}
void solve(int col,int _id,int x=1){
    if(c[x]==col){
        pnt[_id][x]+=1;
        chd[_id][x]+=1;
    }
    for(int i:v[x]){
        chd[_id][i]+=chd[_id][x];
        solve(col,_id,i);
        pnt[_id][x]+=pnt[_id][i];
    }
}
int bit[N];
void add(int x,int val){
    for(;x<N;x+=lowbit(x)){
        bit[x]+=val;
    }
}
int qry(int x){
    int ret=0;
    for(;x>0;x-=lowbit(x)) ret+=bit[x];
    return ret;
}
int bruforce(int c1,int c2){
    vector<pii> p1;
    vector<pii> p2;
    for(int x:cnt[c1]) p1.eb(in[x],out[x]),add(out[x],1);
    for(int x:cnt[c2]) p2.eb(in[x],out[x]);
    sort(all(p1));
    sort(all(p2));
    int l=0;
    int ans=0;
    rep(i,0,sz(p2)-1){
        while(l<sz(p1)&&p1[l].F<=p2[i].F) {
            add(p1[l++].S,-1);
        }
        ans+=qry(p2[i].S);
    }
    while(l<sz(p1)) {
        add(p1[l++].S,-1);
    }
    return ans;
}
long long cntchild(int Id,int r1){
    long long ans=0;
    for(int j:cnt[r1]){
        ans+=chd[Id][j];
    }
    return ans;
}
long long cntpnt(int Id,int r2){
    long long ans=0;
    for(int j:cnt[r2]){
        ans+=pnt[Id][j];
    }
    return ans;
}
signed main(){
	quick
    
    int n,r,q;
    cin>>n>>r>>q;
    cin>>c[1];
    cnt[c[1]].eb(1);
    rep(i,2,n){
        int p;
        cin>>p>>c[i];
        cnt[c[i]].eb(i);
        v[p].eb(i);
    }
    dfs(1);
    int ID=0;
    rep(i,1,r){
        if(sz(cnt[i])>=K){
            idx[i]=ID++;
            solve(i,ID);
            idx[i]=ID;
            ID+=1;
        }
    }
    assert(ID<K);
    while(q--){
        int r1,r2;
        cin>>r1>>r2;
        if(sz(cnt[r1])<K&&sz(cnt[r2])<K){
            cout<<bruforce(r2,r1)<<endl;
        }
        else if(sz(cnt[r1])>sz(cnt[r2])){
            cout<<cntchild(idx[r1],r2)<<endl;
        }
        else cout<<cntpnt(idx[r2],r1)<<endl;
    }
}

Compilation message (stderr)

regions.cpp:23:15: warning: overflow in conversion from 'double' to 'int' changes value from '1.0e+18' to '2147483647' [-Woverflow]
   23 | const int INF=1e18;
      |               ^~~~

• Subtask 1: 15 / 15
• Subtask 2: 80 / 85