Submission #687163

#	Time	Username	Problem	Language	Result	Execution time	Memory
687163		boyliguanhan	Regions (IOI09_regions)	C++17	90 / 100	8058 ms	82388 KiB

regions

#include<bits/stdc++.h>
#pragma GCC optimize(3)
#define l long long
using namespace std;
vector<l> adj[200001], lg;
vector<pair<l,l>> arr[25001];
l region[200001], t, ans1[21][25001], ans2[25001][21], in[200001], out[200001], li[200001], sz[25001];
void merge(unordered_map<l, l> &a, unordered_map<l, l> b){
    if(a.size()<b.size())
        swap(a, b);
    for(auto i: b)
        a[i.first]+=i.second;
}
unordered_map<l,l> dfs(l n){
    unordered_map<l,l> cur;
    cur[region[n]]=1;
    in[n]=t++;
    arr[region[n]].push_back({in[n],1});
    for(auto i: adj[n]){
        merge(cur, dfs(i));
    }
    out[n]=t++;
    arr[region[n]].push_back({out[n],0});
    if(li[region[n]])
        for(auto i: cur)
            ans1[li[region[n]]][i.first]+=i.second;
    else
        for(auto i: lg)
            ans2[region[n]][li[i]]+=cur[i];
    return cur;
}
l query_s(int r1, int r2){
    l sum=0, o=0, a=0, b=0;
    vector<int> v;
    while(a<arr[r1].size()||b<arr[r2].size()){
        if(a<arr[r1].size()&&b<arr[r2].size()){
            if(arr[r1][a]<arr[r2][b])
                v.push_back(arr[r1][a].second*2-1), a++;
            else
                v.push_back(0), b++;
        } else if(a<arr[r1].size())
            v.push_back(arr[r1][a].second*2-1), a++;
        else
            v.push_back(0), b++;
    }
    for(auto i: v)
        if(i)
            o+=i;
        else
            sum+=o;
    return sum/2;
}
int main(){
    iostream::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    l n, r, q, lr=0;
    cin >> n >> r >> q;
    cin >> region[1];
    for(l i = 2; i <= n; i++){
        l p;
        cin >> p >> region[i];
        sz[region[i]]++;
        adj[p].push_back(i);
    }
    for(int i = 1; i <= r; i++)
        if(sz[i]>10000)
            lg.push_back(i), li[i]=++lr;
    dfs(1);
    while(q--){
        int r1, r2;
        cin >> r1 >> r2;
        if(li[r1])
            cout << ans1[li[r1]][r2] << endl;
        else if(li[r2])
            cout << ans2[r1][li[r2]] << endl;
        else
            cout << query_s(r1, r2) << endl;
    }
    return 0;
}

Compilation message (stderr)

regions.cpp: In function 'long long int query_s(int, int)':
regions.cpp:35:12: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |     while(a<arr[r1].size()||b<arr[r2].size()){
      |           ~^~~~~~~~~~~~~~~
regions.cpp:35:30: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |     while(a<arr[r1].size()||b<arr[r2].size()){
      |                             ~^~~~~~~~~~~~~~~
regions.cpp:36:13: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |         if(a<arr[r1].size()&&b<arr[r2].size()){
      |            ~^~~~~~~~~~~~~~~
regions.cpp:36:31: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |         if(a<arr[r1].size()&&b<arr[r2].size()){
      |                              ~^~~~~~~~~~~~~~~
regions.cpp:41:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |         } else if(a<arr[r1].size())
      |                   ~^~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 75 / 85