Submission #794588

#	Time	Username	Problem	Language	Result	Execution time	Memory
794588		Cookie	Regions (IOI09_regions)	C++14	55 / 100	3653 ms	131072 KiB

regions

#include<bits/stdc++.h>
#include<fstream>
using namespace std;
 
#define ll long long
#define pb push_back
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
#define ld long double
#define vt vector
#include<fstream>
#define fi first
#define se second
#define pll pair<ll, ll>
#define pii pair<int, int>
const ld PI = 3.14159265359;
const ll mod = 1e9 + 7;
const int mxn = 5e5 + 5, mxm = 1e5, sq = 800;
const ld inf = 1e9;
int n, r, q, root;
int colour[mxn + 1], tin[mxn + 1], tout[mxn + 1], tt = 0, cnt[mxn + 1];
vt<int>vec[mxn + 1], adj[mxn + 1], to[mxn + 1];
vt<ll>ansb[mxn + 1];
void dfs(int s, int pre){
    tin[s] = ++tt;
    for(auto i: adj[s]){
        if(i != pre){
            dfs(i, s);
        }
    }
    tout[s] = tt;
}
struct th{
    int id, pos, type;
    bool operator <(const th &b){
        if(pos != b.pos)return(pos < b.pos);
        if(type != b.type)return(type < b.type);
        return(id > b.id);
    }
};
 
void solvebig(int i){
    vt<th>comp;
    for(auto k: vec[i]){
        comp.pb({0, tin[k], -1}); comp.pb({0, tout[k],1});
    }
    for(int j = 1; j <= r; j++){
        if(j != i){
           for(auto k: vec[j]){
                comp.pb({k, tin[k], -1}); comp.pb({k, tout[k], 1});
                        
            } 
        }
    }
    sort(comp.begin(), comp.end());
    ll cnt =0 ;
    for(auto [id, pos, type]: comp){
        if(id == 0){
            if(type == 1)cnt++;
            else cnt--;
        }else{
            if(type == 1)ansb[i][id] -= cnt;
            else ansb[i][id] += cnt;
        }
    }
    
    
}
signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> n >> r >> q;
    cin >> colour[1];
    vec[colour[1]].pb(1);
    for(int i = 2; i <= n; i++){
        int p;
        cin >> p >> colour[i]; cnt[colour[i]]++;
        vec[colour[i]].pb(i); adj[p].pb(i);
    }
    dfs(1, -1);
    for(int i = 1; i <= r; i++){
        for(auto j: vec[i]){
            to[i].pb(tin[j]);
        }
        sort(to[i].begin(), to[i].end());
    }
    for(int i = 1; i <= r; i++){
        if(cnt[i] >= sq){
            ansb[i].resize(r + 1);
            solvebig(i);
        }
    }
    while(q--){
        int r1, r2; cin >> r1 >> r2;
        if(cnt[r1] >= sq){
            cout << ansb[r1][r2] << endl;
        }else{
            ll ans = 0;
            for(auto i: vec[r1]){
                
                int idl = lower_bound(to[r2].begin(), to[r2].end(), tin[i]) - to[r2].begin();
                int idr = upper_bound(to[r2].begin(), to[r2].end(), tout[i]) - to[r2].begin() - 1;
                ans += 1LL * (idr - idl + 1);
            }
            cout << ans << endl;
        }
    }
    return(0);
}

Compilation message (stderr)

regions.cpp: In function 'void solvebig(int)':
regions.cpp:57:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   57 |     for(auto [id, pos, type]: comp){
      |              ^

• Subtask 1: 15 / 15
• Subtask 2: 40 / 85