Submission #318754

#	Time	Username	Problem	Language	Result	Execution time	Memory
318754		BeanZ	Bridges (APIO19_bridges)	C++14	100 / 100	2618 ms	131676 KiB

bridges

// I_Love_LPL
#include <bits/stdc++.h>
using namespace std;
#define ll int
#define endl '\n'
const int N = 1e5 + 5;
vector<pair<ll, ll>> rb;
vector<ll> join[N];
ll u[N], v[N], d[N], t[N], a[N], b[N], ch[N], p[N], ans[N];
void rollback(ll u){
    while (rb.size() > u){
        p[rb.back().first] = rb.back().second;
        rb.pop_back();
    }
}
ll find_set(ll u){
    if (p[u] < 0) return u;
    return find_set(p[u]);
}
void dsu(ll u, ll v){
    u = find_set(u);
    v = find_set(v);
    if (u == v) return;
    if (p[u] > p[v]) swap(u, v);
    rb.push_back({u, p[u]});
    rb.push_back({v, p[v]});
    p[u] += p[v];
    p[v] = u;
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    if (fopen("A.inp", "r")){
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    ll n, m;
    cin >> n >> m;
    for (int i = 1; i <= m; i++){
        cin >> u[i] >> v[i] >> d[i];
    }
    ll q;
    cin >> q;
    for (int i = 1; i <= q; i++){
        cin >> t[i] >> a[i] >> b[i];
    }
    const int base = 1000;
    for (int l = 1; l <= q; l += base){
        for (int i = 1; i <= n; i++) p[i] = -1;
        ll r = min(l + base - 1, q);
        for (int i = 1; i <= m; i++) ch[i] = 0;
        rb.clear();
        vector<ll> memupd, memres, un;
        for (int i = l; i <= r; i++){
            if (t[i] == 1) memupd.push_back(a[i]);
        }
        for (int i = l; i <= r; i++){
            if (t[i] == 1){
                d[a[i]] = b[i];
                ch[a[i]] = 1;
            } else {
                for (auto j : memupd){
                    if (d[j] >= b[i]){
                        join[i].push_back(j);
                    }
                }
                memres.push_back(i);
            }
        }
        for (int i = 1; i <= m; i++){
            if (ch[i] == 0) un.push_back(i);
        }
        sort(un.begin(), un.end(), [&](ll g, ll h){return d[g] > d[h];});
        sort(memres.begin(), memres.end(), [&](ll g, ll h){return b[g] > b[h];});
        ll now = 0;
        //for (auto j : memres) cout << j << " ";
        //cout << endl;
        for (auto j : memres){
            while (now < un.size() && d[un[now]] >= b[j]){
                dsu(u[un[now]], v[un[now]]);
                //cout << u[un[now]] << " " << v[un[now]] << " " << now << " " << a[j] << " " << j << endl;
                now++;
            }
            ll tmp = rb.size();
            for (auto o : join[j]){
                dsu(u[o], v[o]);
            }
            //cout << b[j] << endl;
            //cout << j << endl;
            ans[j] = -p[find_set(a[j])];
            //cout << j << " " << ans[j] << endl;
            rollback(tmp);
        }
    }
    for (int i = 1; i <= q; i++){
        if (t[i] == 2) cout << ans[i] << endl;
    }
}
/*
3 4
1 2 5
2 3 2
3 1 4
2 3 8
1
2 1 5
*/

Compilation message (stderr)

bridges.cpp: In function 'void rollback(int)':
bridges.cpp:11:22: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   11 |     while (rb.size() > u){
      |            ~~~~~~~~~~^~~
bridges.cpp: In function 'int main()':
bridges.cpp:79:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |             while (now < un.size() && d[un[now]] >= b[j]){
      |                    ~~~~^~~~~~~~~~~
bridges.cpp:34:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   34 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:35:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   35 |         freopen("test.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