Submission #935496

#	Time	Username	Problem	Language	Result	Execution time	Memory
935496		peterandvoi	Bridges (APIO19_bridges)	C++17	59 / 100	3042 ms	8572 KiB

bridges

#include <bits/stdc++.h>

using namespace std;

#ifdef ngu
#include "debug.h"
#else
#define debug(...) 42
#endif

const int N = (int) 5e4 + 5;
const int M = (int) 1e5 + 5;
const int S = 320;

int n, m;
int lab[N];
int t[M];
int b[M];
int R[M];
int res[M];
int w[M];
bool has[M];
pair<int, int> e[M];
bool modify[M];
stack<pair<int, int>> st;

int get(int u) {
    return lab[u] < 0 ? u : get(lab[u]);
}

void unite(int u, int v, bool roll_back) {
    u = get(u);
    v = get(v);
    if (u != v) {
        if (lab[u] > lab[v]) {
            swap(u, v);
        }
        lab[u] += lab[v];
        if (roll_back) {
            st.emplace(v, -lab[v]);
        }
        lab[v] = u;
    }
}

void rollback() {
    while ((int) st.size()) {
        auto [v, sz] = st.top();
        st.pop();
        int u = lab[v];
        lab[v] = -sz;
        lab[u] -= lab[v];
    }
}

int sz(int u) {
    return -lab[get(u)];
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    #ifdef ngu
    freopen("test.inp", "r", stdin);
    freopen("test.out", "w", stdout);
    #endif
    cin >> n >> m;
    for (int i = 1; i <= m; ++i) {
        int u, v, d;
        cin >> u >> v >> d;
        e[i] = {u, v};
        w[i] = d;
    }
    int q;
    cin >> q;
    for (int i = 1; i <= q; ++i) {
        cin >> t[i] >> b[i] >> R[i];
        t[i]--;
    }
    for (int B = 0; B <= q / S; ++B) {
        int l = max(1, B * S);
        int r = min(q, (B + 1) * S - 1);
        fill(modify + 1, modify + m + 1, false);
        fill(lab + 1, lab + n + 1, -1);
        while ((int) st.size()) {
            st.pop();
        }
        vector<int> qry;
        for (int i = l; i <= r; ++i) {
            if (t[i] == 0) {
                modify[b[i]] = true;
            } else {
                qry.emplace_back(i);
            }
        }
        vector<int> ord, change;
        for (int i = 1; i <= m; ++i) {
            if (!modify[i]) {
                ord.emplace_back(i);
            } else {
                change.emplace_back(i);
            }
        }
        sort(ord.begin(), ord.end(), [&](int u, int v) {
            return w[u] > w[v];
        });
        sort(qry.begin(), qry.end(), [&](int u, int v) {
            return R[u] > R[v];
        });
        int j = -1;
        for (int i : qry) {
            while (j + 1 < (int) ord.size() && w[ord[j + 1]] >= R[i]) {
                j++;
                auto [u, v] = e[ord[j]];
                unite(u, v, false);
            }
            for (int k = i; k >= l; --k) {
                if (t[k] == 0) {
                    if (R[k] >= R[i] && !has[b[k]]) {
                        auto [u, v] = e[b[k]];
                        unite(u, v, true);
                    }
                    has[b[k]] = true;
                }
            }
            for (int k : change) {
                if (!has[k] && w[k] >= R[i]) {
                    auto [u, v] = e[k];
                    unite(u, v, true);
                }
            }
            res[i] = sz(b[i]);
            rollback();
            for (int k = l; k <= i; ++k) {
                if (!t[k]) {
                    has[b[k]] = false;
                }
            }
        }
        for (int i = l; i <= r; ++i) {
            if (!t[i]) {
                w[b[i]] = R[i];
            }
        }
    }
    for (int i = 1; i <= q; ++i) {
        if (t[i] == 1) {
            cout << res[i] << "\n";
        }
    }
}

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