Submission #971569

#	Time	Username	Problem	Language	Result	Execution time	Memory
971569		Cookie	Phone Plans (CCO22_day2problem2)	C++14	25 / 25	1625 ms	159664 KiB

Main

#include<bits/stdc++.h>
#include<fstream>
using namespace std;
#define sz(a) (int)a.size()
#define ALL(v) v.begin(), v.end()
#define ALLR(v) v.rbegin(), v.rend()
#define ll long long
#define pb push_back
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
#define ld long double
#define vt vector
#include<fstream>
#define fi first
#define se second
#define pll pair<ll, ll>
#define pii pair<int, int>
#define mpp make_pair
const ld PI = 3.14159265359, prec = 1e-9;;
//using u128 = __uint128_t;
//const int x[4] = {1, 0, -1, 0};
//const int y[4] = {0, -1, 0, 1};
const ll mod =1e9 + 7, pr = 31;
const int mxn = 5e5 + 5, mxq = 1e5 + 5, sq = 500, mxv = 5e4 + 1;
//const int base = (1 <<18);
const ll inf = 1e13 + 5, neg = -69420, inf2 = 1e14;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
// have fun!
struct E{
    ll u, v, w;
    bool operator <(const E &other){
        return(w < other.w);
    }
};
struct EV{
    int node, pre, curr;
};
ll n, a, b, k;
ll c2(ll n){
    return(n * (n - 1) / 2);
}
struct DSU{
    ll tot = 0;
    ll pa[mxn + 1], siz[mxn + 1];
    vt<int>node[mxn + 1];
    int fp(int u){
        if(pa[u] == u)return(u);
        return(pa[u] = fp(pa[u]));
    }
    void init(){
        for(int i = 1; i <= n; i++){
            pa[i] = i; siz[i] = 1; node[i].clear(); node[i].pb(i);
        }
        tot = 0;
    }
    vt<EV>unon(int u, int v){
        u = fp(u); v = fp(v);
        vt<EV>events;
        if(u == v)return(events);
        tot += siz[u] * siz[v]; 
        if(siz[u] < siz[v])swap(u, v);
        siz[u] += siz[v]; pa[v] = u;
        for(auto i: node[v]){
            node[u].pb(i); events.pb({i, v, u});
        }
        return(events);
    }
    
};
DSU dsu;
vt<E>edgea, edgeb;
vt<EV>eva[mxn + 1], evb[mxn + 1];
ll canda[mxn + 1], candb[mxn + 1];
int paa[mxn + 1], pab[mxn + 1];
map<pair<int, int>, ll>mp;
void solve(){
    cin >> n >> a >> b >> k;
    if(k == 0){
        cout << 0; return;
    }
    for(int i = 0; i < a; i++){
        int u, v, w; cin >> u >> v >> w;
        edgea.pb({u, v, w});
    }
    for(int i = 0; i < b; i++){
        int u, v, w; cin >> u >> v >> w;
        edgeb.pb({u, v, w});
    }
    sort(ALL(edgea)); sort(ALL(edgeb));

    dsu.init();
    ll ans = inf;
    for(int i = 0; i < sz(edgea); i++){
        eva[i + 1] = dsu.unon(edgea[i].u, edgea[i].v); 
        canda[i + 1] = dsu.tot;
        if(dsu.tot >= k)ans = min(ans, edgea[i].w);
    }
    dsu.init();
    
    for(int i = 0; i < sz(edgeb); i++){
        evb[i + 1] = dsu.unon(edgeb[i].u, edgeb[i].v);
        candb[i + 1] = dsu.tot;
        if(dsu.tot >= k)ans = min(ans, edgeb[i].w);
    }
    for(int i = 1; i <= n; i++){
        paa[i] = i; pab[i] = dsu.fp(i);
        mp[mpp(paa[i], pab[i])]++;
    }
    int rp = b;
    ll sme = 0; // belonging to both sets 
    for(int i = 1; i <= a; i++){
        for(auto [node, pre, curr]: eva[i]){
            //cout << node << " " << pre << " " << curr << "\n";
            mp[mpp(paa[node], pab[node])]--;
            sme -= mp[mpp(paa[node], pab[node])];
            //assert(paa[node] == pre);
            paa[node] = curr;
            sme += mp[mpp(paa[node], pab[node])]; 
            mp[mpp(paa[node], pab[node])]++;
        }
        while(canda[i] + candb[rp] - sme >= k && rp >= 1){
            for(auto [node, pre, curr]: evb[rp]){
                mp[mpp(paa[node], pab[node])]--;
                sme -= mp[mpp(paa[node], pab[node])];
                //assert(pab[node] == curr);
                pab[node] = pre;
                sme += mp[mpp(paa[node], pab[node])]; 
                mp[mpp(paa[node], pab[node])]++;
            }
            rp--;
        }
        
        if(rp != b){
            ans = min(ans, edgea[i - 1].w + edgeb[rp].w);
        }
    }
    cout << ((ans == inf) ? -1 : ans);
}



signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    //freopen("THREE.inp", "r", stdin);
    //freopen("THREE.out", "w", stdout);
    int tt; tt = 1;
    while(tt--){
        solve();

    }
    return(0);
}

Compilation message (stderr)

Main.cpp: In function 'void solve()':
Main.cpp:112:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  112 |         for(auto [node, pre, curr]: eva[i]){
      |                  ^
Main.cpp:122:22: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  122 |             for(auto [node, pre, curr]: evb[rp]){
      |                      ^

• Subtask 1: 6 / 6
• Subtask 2: 5 / 5
• Subtask 3: 6 / 6
• Subtask 4: 8 / 8