Submission #872885

#	Time	Username	Problem	Language	Result	Execution time	Memory
872885		lighton	Keys (IOI21_keys)	C++17	100 / 100	949 ms	259760 KiB

keys

#include<bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

#define all(v) (v).begin(), (v).end()
using namespace std;
using pi = pair<int,int>;
struct CC{
    int grp[300001];
    int fi(int x){
        if(grp[x] == x) return x;
        else return grp[x] = fi(grp[x]);
    }
    void un(int x, int y){
        x = fi(x);
        y = fi(y);
        assert(x!=y);
        grp[x] = y;
    }
} cc;
vector<int> R,U,V,C;
struct CYCLES{
    int grp[300001];
    int siz[300001];
    set<int> components[300001];
    set<int> colors[300001];
    set<pi> edges[300001];
    vector<int> reach[300001];
    int fi(int x){
        if(grp[x] == x) return x;
        else return grp[x] = fi(grp[x]);
    }
    void un(int x, int y){
        x = fi(x);
        y = fi(y);
        assert(x!=y);
        if(siz[x] > siz[y]) swap(x,y);
        siz[y] += siz[x];
        for(auto &i :components[x]){
            components[y].insert(i);
        }
        
        for(auto &i :colors[x]){
            if(colors[y].find(i) == colors[y].end()) {
                colors[y].insert(i);
                auto it = edges[y].lower_bound({i,-1});
                while(it != edges[y].end() && it->first == i){
                    reach[y].push_back(it->second);
                    it = edges[y].erase(it);
                }
            }
        }
        
        for(auto &[i,j] : edges[x]){
            if(colors[y].find(i) != colors[y].end()){
                reach[y].push_back(j);
            }
            else edges[y].insert({i,j});
        }

        for(auto &i : reach[x]) reach[y].push_back(i);
        
        while(reach[y].size() && components[y].find(reach[y].back()) != components[y].end()){
            reach[y].pop_back();
        }
        grp[x] = y;
    }
} cycles;
int N,M;
vector<pi> adj[300001];
int chk[300001];
vector<pi> candidate;
int ans = 1e9;
std::vector<int> find_reachable(std::vector<int> r, std::vector<int> u, std::vector<int> v, std::vector<int> c) {
    N = r.size();
    M = u.size();
    R=r;U=u;V=v;C=c;

    for(int i = 0; i<M; i++){
        adj[U[i]].push_back({V[i],C[i]});
        adj[V[i]].push_back({U[i],C[i]});
    }
    //init
    for(int i = 0; i<N; i++){
        cc.grp[i] = i;
        cycles.grp[i] = i;
    }

    for(int i = 0; i<N; i++){
        cycles.components[i].insert(i);
        cycles.colors[i].insert(R[i]);
        for(auto &j : adj[i]){
            if(j.second == R[i]) cycles.reach[i].push_back(j.first);
            else cycles.edges[i].insert({j.second,j.first});
            cycles.siz[i]++;
        }
        while(cycles.reach[cycles.fi(i)].size() && cc.fi(cycles.reach[cycles.fi(i)].back()) == cc.fi(i)){
            cycles.un(i,cycles.reach[cycles.fi(i)].back());
        }
        if(cycles.reach[cycles.fi(i)].empty()){
            int tmp = cycles.components[cycles.fi(i)].size();
            for(int j : cycles.components[cycles.fi(i)]) candidate.push_back({j,tmp});
            ans = min(ans,tmp);
        }
        else{
            cc.un(cycles.reach[cycles.fi(i)].back(),i);
        }
    }

    std::vector<int> ret(N, 0);
    for(auto &[i,j] : candidate){
        if(j==ans) ret[i] = 1;
    }
    return ret;
}

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 17 / 17
• Subtask 4: 30 / 30
• Subtask 5: 33 / 33