Submission #173217

#	Time	Username	Problem	Language	Result	Execution time	Memory
173217		TAISA_	Bridges (APIO19_bridges)	C++14	30 / 100	3068 ms	39288 KiB

bridges

#include <bits/stdc++.h>
#pragma GCC target("avx2")
#define all(vec) vec.begin(), vec.end()
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
constexpr ll INF = (1LL << 30) - 1LL;
constexpr ll LINF = (1LL << 60) - 1LL;
constexpr ll MOD = 1e9 + 7;
template <typename T> void chmin(T &a, T b) { a = min(a, b); }
template <typename T> void chmax(T &a, T b) { a = max(a, b); }
int u[100000], v[100000], d[100000], par[50000], siz[50000];
int t[100000], s[100000], w[100000], vis[100000], res[100000], tmp[100000];
struct UnionFind {
    void build(int n) {
        for (int i = 0; i < n; i++) {
            par[i] = i, siz[i] = 1;
        }
    }
    inline int find(int x) {
        if (par[x] == x) {
            return x;
        } else {
            return par[x] = find(par[x]);
        }
    }
    inline void unite(int u, int v) {
        u = find(u), v = find(v);
        if (u == v)
            return;
        if (siz[u] < siz[v])
            swap(u, v);
        par[v] = u;
        siz[u] += siz[v];
    }
    bool same(int u, int v) { return find(u) == find(v); }
};
stack<int> G[50000];
int ok[50000];
stack<int> vv;
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    const int b = 500;
    int n, m;
    cin >> n >> m;
    vector<P> es(m);
    for (int i = 0; i < m; i++) {
        cin >> u[i] >> v[i] >> d[i];
        --u[i];
        --v[i];
    }
    int q;
    cin >> q;
    fill(res, res + q, -1);
    fill(tmp, tmp + m, -1);
    priority_queue<pair<P, int>> qs;
    UnionFind uf;
    for (int i = 0; i < q; i++) {
        cin >> t[i] >> s[i] >> w[i];
        --s[i];
    }
    vector<int> os;
    int ot = 0;
    for (int i = 0; i < q; i++) {
        if (t[i] == 1) {
            vis[s[i]] = 1;
            os.emplace_back(i);
        } else {
            qs.push(make_pair(P(w[i], s[i]), i));
        }
        if (i % b < b - 1 && i != q - 1) {
            continue;
        }
        for (int j = 0; j < m; j++) {
            es[j] = P(d[j], j);
        }
        sort(all(es), greater<P>());
        int id = 0;
        uf.build(n);
        int fs = (i / b) * b;
        while (!qs.empty()) {
            int ww = qs.top().first.first, st = qs.top().first.second,
                idx = qs.top().second;
            qs.pop();
            while (id < m && es[id].first >= ww) {
                if (!vis[es[id].second]) {
                    uf.unite(u[es[id].second], v[es[id].second]);
                }
                id++;
            }
            for (int k = ot; k < os.size(); k++) {
                if (os[k] >= idx) {
                    break;
                }
                tmp[s[os[k]]] = w[os[k]];
            }
            int to = INF;
            for (int k = ot; k < os.size(); k++) {
                if (os[k] >= idx) {
                    to = k;
                    break;
                }
                if (w[os[k]] == tmp[s[os[k]]] && w[os[k]] >= ww) {
                    int uu = uf.find(u[s[os[k]]]), vv = uf.find(v[s[os[k]]]);
                    G[uu].push(uf.find(vv));
                    G[vv].push(uf.find(uu));
                }
            }
            for (int k = to; k < os.size(); k++) {
                if ((tmp[s[os[k]]] == -1 ? d[s[os[k]]] : tmp[s[os[k]]]) >= ww) {
                    int uu = uf.find(u[s[os[k]]]), vv = uf.find(v[s[os[k]]]);
                    G[uu].push(uf.find(vv));
                    G[vv].push(uf.find(uu));
                }
            }
            for (int k = ot; k < os.size(); k++) {
                if (os[k] >= idx) {
                    break;
                }
                tmp[s[os[k]]] = -1;
            }
            int p = uf.find(st);
            stack<int> ss;
            ss.push(p);
            while (!ss.empty()) {
                int e = ss.top();
                ss.pop();
                ok[e] = 1;
                vv.push(e);
                while (!G[e].empty()) {
                    if (!ok[G[e].top()]) {
                        ok[G[e].top()] = 1;
                        ss.push(G[e].top());
                    }
                    G[e].pop();
                }
            }
            res[idx] = 0;
            while (!vv.empty()) {
                res[idx] += siz[uf.find(vv.top())];
                ok[uf.find(vv.top())] = 0;
                vv.pop();
            }
            for (int k = ot; k < os.size(); k++) {
                int uu = uf.find(u[s[os[k]]]), vv = uf.find(v[s[os[k]]]);
                while (!G[uu].empty()) {
                    G[uu].pop();
                }
                while (!G[vv].empty()) {
                    G[vv].pop();
                }
            }
        }
        for (int j = (int)os.size() - 1; j >= ot; j--) {
            if (vis[s[os[j]]]) {
                d[s[os[j]]] = w[os[j]];
                vis[s[os[j]]] = 0;
            }
        }
        ot = os.size();
    }
    for (int i = 0; i < q; i++) {
        if (res[i] != -1) {
            cout << res[i] << '\n';
        }
    }
}

Compilation message (stderr)

bridges.cpp: In function 'int main()':
bridges.cpp:92:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int k = ot; k < os.size(); k++) {
                              ~~^~~~~~~~~~~
bridges.cpp:99:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int k = ot; k < os.size(); k++) {
                              ~~^~~~~~~~~~~
bridges.cpp:110:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int k = to; k < os.size(); k++) {
                              ~~^~~~~~~~~~~
bridges.cpp:117:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int k = ot; k < os.size(); k++) {
                              ~~^~~~~~~~~~~
bridges.cpp:145:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int k = ot; k < os.size(); k++) {
                              ~~^~~~~~~~~~~
bridges.cpp:81:13: warning: unused variable 'fs' [-Wunused-variable]
         int fs = (i / b) * b;
             ^~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 16
• Subtask 3: 17 / 17
• Subtask 4: 0 / 14
• Subtask 5: 0 / 13
• Subtask 6: 0 / 27