Submission #1269000

#	Time	Username	Problem	Language	Result	Execution time	Memory
1269000		hoa208	Bridges (APIO19_bridges)	C++20	100 / 100	1394 ms	457264 KiB

bridges

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++)
#define FORD(i, b, a) for (int i = (b), _a = (a); i >= _a; i--)
#define pa pair<ll, ll>
#define fi first
#define se second
#define bit(mask, j) ((mask >> j) & 1)
const   ll mod = 1e9 + 7;
const   ll INF = 1e18;
//--------------------------------------------------------------------
const int N = 1e5 + 10;
const int BLOCK = 1000;
const int M = 1e5 + 10;
int p[N], sz[N];
vector<int> edges;
int findset(int u)
{
    return u == p[u] ? u : u = findset(p[u]);
}
void ghep(int u, int v)
{
    u = findset(u);
    v = findset(v);
    if(u == v) return;
    if(sz[u] < sz[v]) {
        swap(u, v);
    }
    edges.push_back(v);
    p[v] = u;
    sz[u] += sz[v];
}
void rollback() {
    int v = edges.back();
    sz[p[v]] -= sz[v];
    p[v] = v;
    edges.pop_back();
}
int n, m, q;
struct ED {
    int u, v, d;
} ed[M];
struct QR {
    int t, x, y;
} qr[M];
int dx[M];
struct B {
    int u, v, d, id;
    bool operator < (const B & a) const {
        return d > a.d || d == a.d && id < a.id;
    }
} b[M + BLOCK];
int ans[M];
vector<pa> vr[N];
void hbmt() {
    cin >> n >> m;
    FOR(i, 1, m) {
        int u, v, d;
        cin >> u >> v >> d;
        ed[i] = {u, v, d};
    }
    FOR(i, 1, n) {
        p[i] = i;
        sz[i] = 1;
    }
    cin >> q;
    int cnt = 0;
    vector<int> q1, q2;
    FOR(i, 1, q) {
        int t, x, y;
        cin >> t >> x >> y;
        qr[i] = {t, x, y};
        cnt++;
        if(t == 1) {
            q1.push_back(x);
        }
        else {
            q2.push_back(i);
        }
        if(i % BLOCK == 0 || i == q) {
            int o = 0;
            int pre = max(1, i - cnt + 1);
            cnt = 0;
            FOR(j, pre, i) {
                if(qr[j].t == 1) {
                    int s = qr[j].x, w = qr[j].y;
                    ed[s].d = w;
                    dx[s] = 1;
                }
                else {
                    int u = qr[j].x, w = qr[j].y;
                    for(auto & e : q1) {
                        if(ed[e].d >= qr[j].y)
                        vr[j].push_back({e, ed[e].d});
                    }
                    b[++o] = {u, 0, w, j};
                }
            }
            FOR(i, 1, m) {
                if(dx[i]) {
                    dx[i] = 0;
                    continue;
                }
                b[++o] = {ed[i].u, ed[i].v, ed[i].d, -1};
            }
            sort(b + 1, b + o + 1);
            FOR(j, 1, o) {
                if(b[j].id == -1) {
                    ghep(b[j].u, b[j].v);
                }
                else {
                    int presz = edges.size();
                    for(auto &e : vr[b[j].id]) {
                        ghep(ed[e.fi].u, ed[e.fi].v);
                    }
                    ans[b[j].id] = sz[findset(b[j].u)];
                    while(presz < edges.size()) rollback();
                }
            }
            while(edges.size() > 0) rollback();
           for(auto &e : q2) {
            cout << ans[e] << '\n';
            vr[e].clear();
           }
            q1.clear();
            q2.clear();
        }
            
    }
}

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

    #define NAME "hbmt"
    if(fopen(NAME".inp", "r")) {
        freopen(NAME".inp", "r", stdin);
        freopen(NAME".out", "w", stdout);
    }
    
    //int t;cin>>t;while(t--)
    hbmt();
    return 0;
}

Compilation message (stderr)

bridges.cpp: In function 'int main()':
bridges.cpp:140:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  140 |         freopen(NAME".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:141:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  141 |         freopen(NAME".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