Submission #992564

#	Time	Username	Problem	Language	Result	Execution time	Memory
992564		Neco_arc	Bridges (APIO19_bridges)	C++17	100 / 100	1896 ms	20048 KiB

bridges

#include <bits/stdc++.h>
//#include <bits/debug.hpp>

#define ll long long
#define all(x) x.begin(), x.end()
#define Neco "Bridges"
#define resp(x) sort(all(x)), x.resize(unique(all(x)) - x.begin())
#define getbit(x,i) ((x >> i)&1)
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define cntbit(x) __builtin_popcountll(x)
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)
#define maxn (int) 2e5 + 7

using namespace std;

const ll mod = 1e9 + 7; //972663749
const ll base = 911382323;
const int Sqrt = 372;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll GetRandom(ll l, ll r) {
    return uniform_int_distribution<ll> (l, r)(rng);
}

int n, m, q, DEL;
int W[maxn], del[maxn], vis[maxn], used[maxn];
int ans[maxn], E[maxn], tmp[maxn];
vector<int> edges[maxn];
struct edge { int u, v; } Ed[maxn];
struct dl { int type, x, w; } qr[maxn];;

struct DSU {
    int lab[maxn];
    void init() { fi(i, 1, n) lab[i] = -1; }
    int get_rt(int u) { return lab[u] < 0 ? u : lab[u] = get_rt(lab[u]); }
    void uni(int u, int v) {
        int p = get_rt(u), q = get_rt(v); if(p == q) return;
        if(lab[p] > lab[q]) swap(p, q);
        lab[p] += lab[q], lab[q] = p;
    }
} Dsu;

int dfs(int u, int del) {
    vis[u] = del;
    int res = Dsu.lab[u];

    for(int v : edges[u]) if(vis[v] != del) {
        res += dfs(v, del);
    }
    return res;
}

void Add(int i) {
    int u = Dsu.get_rt(Ed[qr[i].x].u), v = Dsu.get_rt(Ed[qr[i].x].v);
    edges[u].push_back(v);
    edges[v].push_back(u);
}

void clear(int i) {
    int u = Dsu.get_rt(Ed[qr[i].x].u), v = Dsu.get_rt(Ed[qr[i].x].v);
    edges[u].clear();
    edges[v].clear();
}

void Gen()
{
    n = GetRandom(3, 7), m = GetRandom(3, 9);
    fi(i, 1, m) {
        int u, v;
        u = GetRandom(1, n), v = GetRandom(1, n), W[i] = GetRandom(1, 10);
        E[i] = i;
        Ed[i] = {u, v};
    }
    q = GetRandom(1, 5);
    fi(i, 1, q) {
        qr[i].type = GetRandom(1, 2);
        qr[i].x = GetRandom(1, n);
        qr[i].w = GetRandom(5, 12);
    }

    cout << n << " " << m << '\n';
    fi(i, 1, m) cout << Ed[i].u << " " << Ed[i].v << " " << W[i] << '\n';
    cout << q << '\n';
    fi(i, 1, q) cout << qr[i].type << " " << qr[i].x << " " << qr[i].w << '\n';

    cout << "--------------\n";

}

void Input() {
    cin >> n >> m;
    fi(i, 1, m) {
        int u, v; cin >> u >> v >> W[i];
        E[i] = i;
        Ed[i] = {u, v};
    }
    cin >> q;
    fi(i, 1, q) cin >> qr[i].type >> qr[i].x >> qr[i].w;
}

void solve()
{

    Input();
//    Gen();

    sort(E + 1, E + 1 + m, [](int x, int y) { return W[x] > W[y]; });
    vector<dl> P;

    for(int T = 1; T <= (q - 1) / Sqrt + 1; ++T)
    {
        int L = (T - 1) * Sqrt + 1, R = min(q, Sqrt * T);
        fi(i, L, R) {
            if(qr[i].type == 1) del[qr[i].x] = T;
            else P.push_back({qr[i].x, qr[i].w, i});
        }

        Dsu.init();
        sort(all(P), [](dl x, dl y) { return x.x > y.x; });

        int j = 1;

        for(auto [x, w, id] : P) {
            ++DEL;
            while(W[E[j]] >= w) {
                if(del[E[j]] != T) Dsu.uni(Ed[E[j]].u, Ed[E[j]].v);
                ++j;
            }

            fi(i, L, R) if(qr[i].type == 1) tmp[qr[i].x] = W[qr[i].x];
            fi(i, L, id) if(qr[i].type == 1) W[qr[i].x] = qr[i].w;

            fi(i, L, R) if(qr[i].type == 1 && W[qr[i].x] >= w) Add(i);

            ans[id] = - dfs(Dsu.get_rt(x), DEL);

            fi(i, L, R) if(qr[i].type == 1 && W[qr[i].x] >= w) clear(i);
            fi(i, L, R) if(qr[i].type == 1) W[qr[i].x] = tmp[qr[i].x];
        }


        fi(i, L, R) if(qr[i].type == 1) W[qr[i].x] = qr[i].w;
        sort(E + 1, E + 1 + m, [](int x, int y) { return W[x] > W[y]; });
        P.clear();
    }

    fi(i, 1, q) if(qr[i].type == 2) cout << ans[i] << '\n';

}


int main()
{

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if(fopen(Neco".inp", "r")) {
        freopen(Neco".inp", "r", stdin);
        freopen(Neco".out", "w", stdout);
    }


    int nTest = 1;
//    cin >> nTest;


    while(nTest--)
    {
        solve();
    }


    return 0;
}

Compilation message (stderr)

bridges.cpp: In function 'int main()':
bridges.cpp:162:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  162 |         freopen(Neco".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:163:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  163 |         freopen(Neco".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