Submission #540310

#	Time	Username	Problem	Language	Result	Execution time	Memory
540310		Lobo	Bridges (APIO19_bridges)	C++17	60 / 100	3056 ms	9952 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<int> g[maxn];
vector<pair<int,int>> g1[maxn];

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

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

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

int cnt;
void bfs(int u, int val, int idq) {
    mark[u] = idq;
    cnt+= dsz[u];
    for(auto V : g1[u]) {
        int v = V.fr;
        int w = d[V.sc];

        if(mark[v] == idq || w < val) continue;
        bfs(v,val,idq);
    }
}

// void bfs(int beg, int val, int idq) {
//     queue<int> q;
//     q.push(beg);
//     mark[beg] = idq;
//     while(q.size()) {
//         int u = q.front();
//         q.pop();
//         cnt+= dsz[u];
//         for(auto V : g1[u]) {
//             int v = V.fr;
//             int w = d[V.sc];

//             if(mark[v] == idq || w < val) continue;
//             mark[v] = idq;
//             q.push(v);
//         }   
//     }
// }

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

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

        g[a[i]].pb(i);
        g[b[i]].pb(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;
        vector<pair<int,pair<int,int>>> atts;
        for(int i = 1; i <= Bq; i++) {
            int op; cin >> op;

            if(op == 1) {
                int id,val; cin >> id >> val;
                chg[id] = j;
                atts.pb(mp(i,mp(id,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

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

        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;

                for(auto x : atts) {
                    if(x.fr > X.sc) break;
                    int id = x.sc.fr;
                    int w = x.sc.sc;
                    // cout << "    " << id << " - " << w << endl;
                    // cout << "   " << find(a[id]) << " " << find(b[id]) << endl;
                    d[id] = w;
                    g1[find(a[id])].pb(mp(find(b[id]),id));
                    g1[find(b[id])].pb(mp(find(a[id]),id));
                }

                cnt = 0;
                bfs(find(u),val,idq);
                ans[idq] = cnt;
                for(auto x : atts) {
                    if(x.fr > X.sc) break;
                    int id = x.sc.fr;
                    int w = x.sc.sc;
                    d[id] = w;
                    g1[find(a[id])].pop_back();
                    g1[find(b[id])].pop_back();
                }
            }
        }

        for(auto x : atts) {
            int id = x.sc.fr;
            int w = x.sc.sc;
            d[id] = w;
        }

        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: 0 / 13
• Subtask 6: 0 / 27