Submission #484685

#	Time	Username	Problem	Language	Result	Execution time	Memory
484685		Killer2501	Bridges (APIO19_bridges)	C++14	100 / 100	2079 ms	16352 KiB

bridges

#include <bits/stdc++.h>
#define ll int
#define ld long double
#define ull unsigned long long
#define pb push_back
#define pll pair<ll, ll>
#define pii pair<ll, pll>
#define fi first
#define se second
using namespace std;
const int N = 2e5+5;
const int M = 405;
const ll mod = 1e9;
const ll base = 350;
const ll inf = 1e9  ;

ll n, m, t, q, k, ans, a[N], b[N], tong, in[N], out[N], res[N], x[N], y[N], w[N], id[N];
vector<ll> adj[N];
struct DSU
{
    ll n;
    vector<ll> lab;
    vector<pair<pll, pll>> snap;
    DSU(ll _n)
    {
        n = _n;
        lab.resize(n+1, -1);
    }
    ll findp(ll u)
    {
        return lab[u] < 0 ? u : findp(lab[u]);
    }
    void hop(ll x, ll y)
    {
        ll u = findp(x), v = findp(y);
        if(u == v)return;
        if(lab[u] > lab[v])swap(u, v);
        snap.pb({{u, lab[u]}, {v, lab[v]}});
        lab[u] += lab[v];
        lab[v] = u;
    }
    void rollback(ll sz)
    {
        while((int) snap.size() > sz)
        {
            auto x = snap.back();
            snap.pop_back();
            lab[x.fi.fi] = x.fi.se;
            lab[x.se.fi] = x.se.se;
        }
    }
};
vector<ll> ve;
bool cmp(const ll& x, const ll& y)
{
    return w[x] > w[y];
}
void sol()
{
    cin >> n >> m;
    for(int i = 1; i <= m; i ++)
    {
        cin >> x[i] >> y[i] >> w[i];
        id[i] = i;
        in[i] = i;
        out[i] = inf;
        ve.pb(i);
    }
    cin >> q;
    for(int i = m+1; i <= m+q; i ++)
    {
        cin >> x[i] >> y[i] >> w[i];
        if(x[i] == 1)
        {
            out[id[y[i]]] = i-1;
            id[y[i]] = i;
            in[i] = i;
            out[i] = inf;
            ve.pb(i);
        }
    }
    //for(int i = 1; i <= m+q; i ++)cout << in[i] <<" "<<out[i] << '\n';
    DSU dsu(n);
    sort(ve.begin(), ve.end(), cmp);
    for(int l = m+1; l <= m+q; l += base)
    {
        int r = min(m+q, l+base-1);
        vector<ll> fixed, query, kq;
        for(int i = l; i <= r; i ++)if(x[i] == 2)query.pb(i);
        if(query.empty())continue;
        sort(query.begin(), query.end(), cmp);
        for(int i: ve)
        {
            if(in[i] <= l && out[i] >= r)fixed.pb(i);
            else if(in[i] <= r && out[i] >= l)kq.pb(i);
        }
        int j = 0;
        for(int i: query)
        {
            //cout << i << " ";
            while(j < (int) fixed.size() && w[fixed[j]] >= w[i])
            {
                //cout << fixed[j] << " ";
                if(fixed[j] <= m)dsu.hop(x[fixed[j]], y[fixed[j]]);
                else dsu.hop(x[y[fixed[j]]], y[y[fixed[j]]]);
                ++j;
            }
            k = dsu.snap.size();
            for(int p: kq)
            {
                if(w[p] >= w[i] && in[p] <= i && i <= out[p])
                {
                    //cout << p << " ";
                    if(p <= m)dsu.hop(x[p], y[p]);
                    else dsu.hop(x[y[p]], y[y[p]]);
                }
            }
            //cout << '\n';
            res[i] = -dsu.lab[dsu.findp(y[i])];
            dsu.rollback(k);
        }
        dsu.rollback(0);
    }
    for(int i = m+1; i <= m+q; i ++)if(x[i] == 2)cout << res[i] << '\n';

}
int main()
{
    cin.tie(0);
    cout.tie(0);
    ios_base::sync_with_stdio(0);
    #define task "test"
    if(fopen(task".inp", "r"))
	{
		freopen(task".inp", "r", stdin);
		freopen(task".out", "w", stdout);
	}
    int test = 1;
    //cin >> test;
    while(test -- > 0)sol();
    return 0;
}

Compilation message (stderr)

bridges.cpp: In function 'int main()':
bridges.cpp:135:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  135 |   freopen(task".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:136:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  136 |   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