Submission #1221570

#	Time	Username	Problem	Language	Result	Execution time	Memory
1221570		hoa208	Bridges (APIO19_bridges)	C++20	100 / 100	2833 ms	9784 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)
#define t_test int t;cin >> t;while(t--)
const   ll mod = 1e9 + 7;
const   ll INF = 1e18;
inline  void adm(ll &x){if(x>=mod)x%=mod;else if(x<0)x+=mod;}
//--------------------------------------------------------------------
const ll BLOCK = 350;
const ll N = 5e4 + 10;
const ll M = 1e5 + 10;
ll n, m;
struct EDGE {
    ll u, v, d;
    
};
struct EDGE2 {
    ll u, v, d, id;
    bool operator < (const EDGE2 & a) const {
        return d > a.d || (a.d == d && id < a.id);
    }
};
EDGE ed[M];
vector<ll> edge;
ll dx[M];
pa a[BLOCK + 10];
ll p[N], sz[N];
ll b[BLOCK + 10], res[BLOCK + 10];
ll findset(ll u) {
    if(p[u] == u) return u;
    return findset(p[u]);
}
void rollback() {
    ll v = edge.back();
    edge.pop_back();
    sz[p[v]] -= sz[v];
    p[v] = v;
}
void ghep(ll u, ll v) {
    u = findset(u);
    v = findset(v);
    if(v == u) return;
    if(sz[v] > sz[u]) swap(u, v);
    edge.push_back(v);
    p[v] = u;
    sz[u] += sz[v];
}
void hbmt() {
    cin >> n >> m;
    FOR(i, 1, m) {
        ll u, v, d;
        cin >> u >> v >> d;
        ed[i] = {u, v, d};
    }
    ll q, dem = 0;
    cin >> q;
    vector<EDGE> vt, vr[BLOCK + 10];
    vector<ll> q1;
    vector<EDGE2> ve;
    FOR(i, 1, n) p[i] = i, sz[i] = 1;
    FOR(i, 1, q) {
        ll x, u, v;
        cin >> x >> u >> v;
        if(x == 2) {
            vt.push_back({++dem, u, v});
        }
        else {
            vt.push_back({-1, u, v});
            q1.push_back(u);
        }
        if(i % BLOCK == 0 || i == q) {
            for(auto e : vt) {
                if(e.u != -1) {
                    for(auto id : q1) {
                        vr[e.u].push_back(ed[id]);
                    }
                    ve.push_back({e.v, 0, e.d, e.u});
                }
                else {
                    ed[e.v].d = e.d;
                    dx[e.v] = 1;
                }
            }
            FOR(i, 1, m) {
                if(dx[i]) {
                    dx[i] = 0;
                    continue;
                }
                ve.push_back({ed[i].u, ed[i].v, ed[i].d, -1});
            }
            sort(ve.begin(), ve.end());
            for(auto e : ve) {
                ll u = e.u, v = e.v, w = e.d, id = e.id;
                if(id == -1) ghep(u, v);
                else {
                    ll szz = edge.size();
                    for(auto f : vr[id]) {
                        if(f.d >= w) ghep(f.u, f.v);
                    }
                    res[id] = sz[findset(u)];
                    while(edge.size() > szz) rollback();
                }
            }
            while(edge.size() > 0) rollback();
            FOR(i, 1, dem) {
                vr[i].clear();
                cout << res[i] << '\n';
            }
            vt.clear();
            ve.clear();
            q1.clear();
            dem = 0;
        }
    }
}

int main() {
    
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    
    if(fopen("hbmt.inp", "r")) {
        freopen("hbmt.inp", "r", stdin);
        freopen("hbmt.out", "w", stdout);
    }
    
    // t_test 
    hbmt();
    return 0;
}

Compilation message (stderr)

bridges.cpp: In function 'int main()':
bridges.cpp:129:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  129 |         freopen("hbmt.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:130:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  130 |         freopen("hbmt.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