Submission #683490

#	Time	Username	Problem	Language	Result	Execution time	Memory
683490		Nursik	Bridges (APIO19_bridges)	C++14	100 / 100	2013 ms	12328 KiB

bridges

#include <stdio.h>
 
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;
 
#define ll long long
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define ld long double
#define bug cout << "bug\n";

const int maxn = 1e5 + 1, maxm = 5e4 + 1;
const int mod = 1e9 + 7, inf = 1e9, block = 800, hb = 126067, base = 1000050017;
const ll biginf = 5e18;
const ld eps = 1e-15;
using namespace std;

int n, m, q;
int u[maxn], v[maxn], d[maxn], used[maxn], ans[maxn];
int t[maxn];
int x[maxn], y[maxn];
vector<int> add[block + block];
struct dsu{
    int p[maxm], sz[maxm];
    stack<pair<int, int>> st;
    void init(){
        for (int i = 1; i <= n; ++i){
            p[i] = i, sz[i] = 1;
        }
        while (st.size() > 0){
            st.pop();
        }
    }
    int get(int v){
        if (v == p[v])
            return v;
        return get(p[v]);
    }
    void unite(int a, int b){
        a = get(a), b = get(b);
        if (a == b)
            return;
        if (sz[a] > sz[b])
            swap(a, b);
        p[a] = b;
        sz[b] += sz[a];
        st.push(mp(a, sz[a]));
    }
    void rollback(int y){
        while (st.size() != y){
            pair<int, int> cur = st.top();
            int r = p[cur.f];
            sz[r] -= cur.s;
            p[cur.f] = cur.f;
            st.pop();
        }
    }
} rt;
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    cin >> n >> m;
    for (int i = 1; i <= m; ++i){
        cin >> u[i] >> v[i] >> d[i];
    }
    cin >> q;
    for (int i = 1; i <= q; ++i){
        cin >> t[i];
        if (t[i] == 1){
            cin >> x[i] >> y[i];
        }
        else{
            cin >> x[i] >> y[i];
        }
    }
    for (int i = 1; i <= q; i += block){
        rt.init();
        int l = i, r = min(q, i + block - 1);
        vector<int> changed;
        vector<pair<int, int>> unchanged;
        vector<pair<int, int>> ask;
        for (int j = l; j <= r; ++j){
            if (t[j] == 1){
                used[x[j]] = 1;
                changed.pb(x[j]);
            }
            else{
                ask.pb(mp(y[j], j));
            }
        }
        for (int j = l; j <= r; ++j){
            if (t[j] == 1){
                d[x[j]] = y[j];
            }
            else{
                add[j - l].clear();
                for (auto it : changed){
                    if (d[it] >= y[j]){
                        add[j - l].pb(it);
                    }
                }
            }
        }
        for (int j = 1; j <= m; ++j){
            if (used[j] == 0){
                unchanged.pb(mp(d[j], j));
            }
            used[j] = 0;
        }
        sort(ask.begin(), ask.end());
        sort(unchanged.begin(), unchanged.end());
        int uk = (int)unchanged.size() - 1;
        for (int j = (int)ask.size() - 1; j >= 0; --j){
            while (uk >= 0 && unchanged[uk].f >= ask[j].f){
                int z = unchanged[uk].s;
                rt.unite(u[z], v[z]);
                uk -= 1;
            }
            int cur = (int)rt.st.size();
            int pos = ask[j].s;
            for (auto it : add[pos - l]){
                rt.unite(u[it], v[it]);
            }
            ans[pos] = rt.sz[rt.get(x[pos])];
            rt.rollback(cur);
        }
    }
    for (int i = 1; i <= q; ++i){
        if (t[i] == 2){
            cout << ans[i] << '\n';
        }
    }
}
/*
 */

Compilation message (stderr)

bridges.cpp: In member function 'void dsu::rollback(int)':
bridges.cpp:76:26: warning: comparison of integer expressions of different signedness: 'std::stack<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   76 |         while (st.size() != y){
      |                ~~~~~~~~~~^~~~

• Subtask 1: 13 / 13
• Subtask 2: 16 / 16
• Subtask 3: 17 / 17
• Subtask 4: 14 / 14
• Subtask 5: 13 / 13
• Subtask 6: 27 / 27