Submission #1210590

#	Time	Username	Problem	Language	Result	Execution time	Memory
1210590		garam1732	Keys (IOI21_keys)	C++20	0 / 100	16 ms	36680 KiB

keys

#include <bits/stdc++.h>
using namespace std;

#define ff first
#define ss second
#define bl ' '
#define endl '\n'
#define all(v) (v).begin(), (v).end()
#define comp(v) (v).erase(unique(all(v)), (v).end())
#define lbd(v,x) lower_bound(all(v), (x))-(v).begin()
#define ubd(v,x) upper_bound(all(v), (x))-(v).begin()

typedef long long ll;
typedef pair<int, int> pi;
typedef pair<pi, int> pii;
typedef pair<int, pi> ipi;
typedef pair<pi, pi> pipi;
typedef pair<ll, ll> pll;

const int MAXN = 100100*3;
const ll MOD = 998244353;
const ll INF = 1e16;

vector<pi> adj[MAXN];
int nx[MAXN], idx[MAXN];
vector<int> pv[MAXN];

vector<int> vtx[MAXN];
set<int> col[MAXN];

vector<int> cnct, pnt; 
int root(int x, vector<int>& par) { return par[x]==x?x:par[x]=root(par[x], par); }
void merge(int x, int y, vector<int>& par) {
    x = root(x, par), y = root(y, par);
    if(x^y) par[y] = x;
}

void merge_stl(int a, int b) {
    merge(a, b, pnt);
    for(int x : vtx[b]) {
        vtx[a].push_back(x);
    } for(int x : col[b]) {
        col[a].insert(x);
    } vtx[b].clear(); col[b].clear();
}

queue<vector<int> > cycle;
vector<pi> cand;
vector<int> ans;

int vst[MAXN]; // -1: already vst, 0: not vst, 1: current vst
vector<int> track;
void dfs(int here) {
    vst[here] = 1;
    track.push_back(here);

    int there = nx[here];
    if(there == -1) return;
    if(vst[there] == -1) return;
    if(vst[there] == 1) {
        vector<int> v;
        int i=0; while(track[i]^there) i++;
        for(; i<track.size(); i++) v.push_back(track[i]);
        cycle.push(v); return;
    } dfs(there);
}

int cnt[MAXN];
int num;

std::vector<int> find_reachable(std::vector<int> r, std::vector<int> u, std::vector<int> v, std::vector<int> c) {
	int n = r.size(), m = u.size(); int 테스트=3; 테스트++;
    for(int i=0; i<m; i++) {
        adj[u[i]].push_back(pi(v[i], c[i]));
        adj[v[i]].push_back(pi(u[i], c[i]));
    } for(int i=0; i<n; i++) {
        col[i].insert(r[i]);
        vtx[i].push_back(i);
    }

    cnct.resize(n); pnt.resize(n); ans.resize(n);
    for(int i=0; i<n; i++) cnct[i] = pnt[i] = i;

    // nx init
    bool chk = 0;
    memset(nx, -1, sizeof nx);
    for(int i=0; i<n; i++) {
        for(int &j = idx[i]; j<adj[i].size(); j++) {
            int x = adj[i][j].ff, w = adj[i][j].ss;
            if(w == r[i]) {
                nx[i] = x; pv[x].push_back(i);
                merge(i, nx[i], cnct); break;
            }
        } if(nx[i] == -1) {
            chk=1; ans[i]=1;
        }
    } if(chk) return ans;

    // find cycle
    for(int i=0; i<n; i++) {
        if(!vst[i]) {
            track.clear();
            dfs(i);
            for(int x:track) vst[x]=-1;
        }
    }

    while(cycle.size()) {
        // union cycle
        vector<int> v = cycle.front(); cycle.pop();
        for(int i=1; i<v.size(); i++) {
            if(vtx[v[0]].size() < vtx[v[i]].size()) swap(v[0], v[i]);
            merge_stl(v[0], v[i]);
        }

        // update nx and pv
        vector<int> tmp;
        for(int a : vtx[v[0]]) {
            for(int b : pv[a]) {
                if(root(b, pnt) == v[0]) continue;
                tmp.push_back(b); nx[b] = v[0];
            } pv[a].clear();
        } swap(tmp, pv[v[0]]);

        // update new nx
        bool esc = 0;
        vector<int> new_cycle;
        for(int a : vtx[v[0]]) {
            for(int &j = idx[a]; j<adj[a].size(); j++) {
                int b = adj[a][j].ff, w = adj[a][j].ss; b = root(b, pnt);
                if(b!=v[0] && col[v[0]].find(w)!=col[v[0]].end()) {
                    int x = root(v[0], cnct), y = root(b, cnct);
                    if(x == y) {
                        new_cycle.push_back(v[0]); num++;
                        for(int here = b; here != v[0]; here=nx[here]) {
                            new_cycle.push_back(here);
                            assert(cnt[here]!=num); cnt[here]=num;
                        }
                            
                    } else {
                        nx[v[0]] = b; pv[b].push_back(v[0]);
                        merge(x, y, cnct);
                    }
                    esc = 1; break;
                }
            } if(esc) break;
        }

        // push new cycle
        if(new_cycle.size() > 1) cycle.push(new_cycle);
        else cand.push_back(pi(vtx[v[0]].size(), v[0]));
    }
    
    // return smallest root
    sort(all(cand)); int mn = cand[0].ff;
    for(auto x:cand) {
        if(x.ff==mn) {
            for(int y:vtx[x.ss]) ans[y]=1;
        }
    }

	return ans;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 11
• Subtask 3: 0 / 17
• Subtask 4: 0 / 30
• Subtask 5: 0 / 33