Submission #540315

#	Time	Username	Problem	Language	Result	Execution time	Memory
540315		Lobo	Bridges (APIO19_bridges)	C++17	100 / 100	2786 ms	16324 KiB

bridges

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

const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
// #define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()

const int maxn = 5e4 + 10;
const int B = 800;

int n, m, q, ds[maxn], dsz[maxn], mark[maxn], a[2*maxn], b[2*maxn], d[2*maxn], ans[maxn];
int chg[2*maxn];
vector<pair<int,int>> g1[maxn], atts[2*maxn];

int find(int u) {
    if(ds[u] == u) return u;
    return find(ds[u]);
}

void join(int u, int v) {
    if(dsz[u] < dsz[v]) swap(u,v);

    dsz[u]+= dsz[v];
    ds[v] = u;
}

stack<pair<int,int>> st;
void rollback() {
    int u = st.top().fr;
    int v = st.top().sc;
    st.pop();
    if(dsz[u] < dsz[v]) swap(u,v);
    ds[v] = v;
    dsz[u]-=dsz[v];
}

void solve() {
    cin >> n >> m;

    for(int i = 1; i <= m; i++) {
        cin >> a[i] >> b[i] >> d[i];
    }

    int q; cin >> q;
    for(int j = 1; j <= q; j+=B) {
        int Bq = min(B,q-j+1);

        for(int i = 1; i <= n; i++) {
            g1[i].clear();
        }

        vector<pair<pair<int,int>,int>> qrr;
        for(int i = 1; i <= m; i++) {
            atts[i].clear();
            atts[i].pb(mp(0,d[i]));
        }
        for(int i = 1; i <= Bq; i++) {
            int op; cin >> op;

            if(op == 1) {
                int id,val; cin >> id >> val;
                chg[id] = j;
                atts[id].pb(mp(i,val));
                ans[i] = -1;
            }
            else {
                int id,val; cin >> id >> val;
                qrr.pb(mp(mp(val,-id),i));
                ans[i] = 0;
            }
        }

        //coloco as arestas nao mudadas e as queries juntas e ordedo da maior pra menor
        //quando responto query com peso x ja adicionei todas as arestas nao mudadadas d[i] > x
        //para cada query eu passo por todas as att e mudo / adiciono do jeito certo

        vector<int> edgch;
        for(int i = 1; i <= m; i++) {
            if(chg[i] != j) {
                qrr.pb(mp(mp(d[i],i),0));
            }
            else {
                edgch.pb(i);
            }
        }

        sort(all(qrr),greater<pair<pair<int,int>,int>>());
        for(int i = 1; i <= n; i++) {
            ds[i] = i;
            dsz[i] = 1;
            mark[i] = 0;
        }
        for(auto X : qrr) {
            if(X.fr.sc > 0) {
                //adicionar uma aresta
                int id = X.fr.sc;
                int u = a[id];
                int v = b[id];
                // cout << " " << id << endl;
                u = find(u);
                v = find(v);
                if(u != v) join(u,v);
            }
            else {
                //sai de u com val
                int val = X.fr.fr;
                int u = -X.fr.sc;
                int idq = X.sc;
                // cout << "  " << u << " " << val << " " << idq << endl;
                int cntrll = 0;
                for(auto id : edgch) {
                    //com upperbound
                    auto it = upper_bound(all(atts[id]),mp(idq,0)); it--;
                    if(it->sc >= val) {
                        //adiciona id
                        int v1 = find(a[id]);
                        int v2 = find(b[id]);

                        if(v1 != v2) {
                            st.push(mp(v1,v2));
                            join(v1,v2);
                            cntrll++;
                        }
                    }
                }

                ans[idq] = dsz[find(u)];

                while(cntrll--) rollback();
            }
        }

        for(auto id : edgch) {
            d[id] = atts[id].back().sc;
        }

        for(int i = 1; i <= Bq; i++) {
            if(ans[i] != -1) cout << ans[i] << endl;
        }
    }
}

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(0);

    // freopen("in.in", "r", stdin);
    // freopen("out.out", "w", stdout);

    int tt = 1;
    // cin >> tt;
    while(tt--) solve();

}

• Subtask 1: 13 / 13
• Subtask 2: 16 / 16
• Subtask 3: 17 / 17
• Subtask 4: 14 / 14
• Subtask 5: 13 / 13
• Subtask 6: 27 / 27