Submission #1099466

#	Time	Username	Problem	Language	Result	Execution time	Memory
1099466		lmToT27	Bridges (APIO19_bridges)	C++17	100 / 100	1417 ms	133252 KiB

bridges

#include <bits/stdc++.h>
#define all(dataStructure) dataStructure.begin(),dataStructure.end()
#define ll long long

using namespace std;
namespace std {
        template <typename T, int D>
        struct _vector : public vector <_vector <T, D - 1>> {
                static_assert(D >= 1, "Dimension must be positive!");
                template <typename... Args>
                _vector(int n = 0, Args... args) : vector <_vector <T, D - 1>> (n, _vector <T, D - 1> (args...)) {}
        };
        // _vector <int, 3> a(n, m, k);: int a[n][m][k].
        // _vector <int, 3> a(n, m, k, x);: int a[n][m][k] initialized with x.
        template <typename T>
        struct _vector <T, 1> : public vector <T> {
                _vector(int n = 0, const T& val = T()) : vector <T> (n, val) {}
        };
}

const int MAX = 5e4 + 3;
const ll MOD[] = {1000000007, 998244353};
const int blockSize = 1000;

int n, m, q;
int u[MAX << 1], v[MAX << 1], w[MAX << 1];
int type[MAX << 1], a[MAX << 1], b[MAX << 1];

int pa[MAX], sz[MAX];
vector <int> ops;

int findpa(int u) {
        return u == pa[u] ? u : findpa(pa[u]);
}

void join(int u, int v) {
        u = findpa(u);
        v = findpa(v);
        if (u == v) return;
        if (sz[u] < sz[v]) swap(u, v);
        pa[v] = u;
        sz[u] += sz[v];
        ops.push_back(v);
}

void rollBack() {
        int u = ops.back();
        ops.pop_back();
        sz[pa[u]] -= sz[u];
        pa[u] = u;
}

int ans[MAX << 1];
bool changed[MAX << 1];
vector <int> toJoin[MAX << 1];

void Solve() {
        cin >> n >> m;
        for (int i = 1; i <= m; i++) {
                cin >> u[i] >> v[i] >> w[i];
        }
        cin >> q;
        for (int i = 1; i <= q; i++) {
                cin >> type[i] >> a[i] >> b[i];
        }
        for (int l = 1; l <= q; l += blockSize) {
                ops.clear();
                fill(sz + 1, sz + n + 1, 1);
                fill(changed + 1, changed + m + 1, false);
                iota(pa + 1, pa + n + 1, 1);

                vector <int> asks;
                vector <int> updates;
                vector <int> staticEgs;

                int r = min(l + blockSize - 1, q);
                for (int i = l; i <= r; i++) {
                        if (type[i] == 1) {
                                changed[a[i]] = 1;
                                updates.push_back(a[i]);
                        } else {
                                asks.push_back(i);
                        }
                }
                for (int i = 1; i <= m; i++) if (!changed[i]) {
                        staticEgs.push_back(i);
                }
                for (int i = l; i <= r; i++) {
                        if (type[i] == 1) {
                                w[a[i]] = b[i];
                        } else {
                                for (int &j : updates) {
                                        if (w[j] >= b[i]) {
                                                toJoin[i].push_back(j);
                                        }
                                }
                        }
                }        

                sort(all(asks), [&](const int &i, const int &j) {
                        return b[i] > b[j];
                });

                sort(all(staticEgs), [&](const int &i, const int &j) {
                        return w[i] < w[j];
                });

                int pointer = 0;
                for (int &i : asks) {
                        while (staticEgs.size() && w[staticEgs.back()] >= b[i]) {
                                join(u[staticEgs.back()], v[staticEgs.back()]);
                                staticEgs.pop_back();
                        }
                        int preSz = ops.size();
                        for (int &j : toJoin[i]) {
                                join(u[j], v[j]);
                        }
                        ans[i] = sz[findpa(a[i])];
                        while ((int)ops.size() > preSz) rollBack();
                }

                sort(all(asks));
        
                for (int &i : asks) cout << ans[i] << '\n';
        }
}

int32_t main() {
        ios_base::sync_with_stdio(0);
        cin.tie(0); cout.tie(0);

        #define TASK ""
        if (fopen(TASK".INP", "r")) {
                freopen(TASK".INP", "r", stdin);
                freopen(TASK".OUT", "w", stdout);
        }
                
        if (fopen("TASK.INP", "r")) {
                freopen("TASK.INP", "r", stdin);
                freopen("TASK.OUT", "w", stdout);
        }
        
        /* int TEST = 1; cin >> TEST; while (TEST--) */ Solve();

        cerr << "\nTime elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << "s\n";
        return 0;
}

Compilation message (stderr)

bridges.cpp: In function 'void Solve()':
bridges.cpp:108:21: warning: unused variable 'pointer' [-Wunused-variable]
  108 |                 int pointer = 0;
      |                     ^~~~~~~
bridges.cpp: In function 'int32_t main()':
bridges.cpp:134:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  134 |                 freopen(TASK".INP", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:135:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  135 |                 freopen(TASK".OUT", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:139:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  139 |                 freopen("TASK.INP", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:140:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  140 |                 freopen("TASK.OUT", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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