Submission #682716

#	Time	Username	Problem	Language	Result	Execution time	Memory
682716		Lobo	Political Development (BOI17_politicaldevelopment)	C++17	100 / 100	369 ms	36704 KiB

politicaldevelopment

#include<bits/stdc++.h>
using namespace std;
const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
#define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()
const int maxn = 5e4+10;

int n, k, gr[maxn];
vector<int> g[maxn];
set<int> stg[maxn];

vector<int> vrts,adds;
int bck(int i) {
    if(i == vrts.size()) return adds.size();
    int ans = bck(i+1);
    int u = vrts[i];
    bool ok = true;
    for(auto v : adds) if(stg[u].count(v) == 0) ok = false;

    if(ok) {
        adds.pb(u);
        ans = max(ans, bck(i+1));
        adds.pop_back();
    }
    return ans;
}

void solve() {
    cin >> n >> k;
    int ans = 1;
    for(int i = 0; i < n; i++) {
        int d; cin >> d; 
        gr[i] = d;
        while(d--) {
            int x; cin >> x;
            stg[i].insert(x);
            g[i].pb(x);
        }
    }

    set<pair<int,int>> st;
    for(int i = 0; i < n; i++) {
        st.insert(mp(gr[i],i));
    }

    while(st.size()) {
        int u = st.begin()->sc;
        st.erase(st.begin());
        if(gr[u] >= k) {
            ans = k;
            break;
        }
        vrts.clear();
        adds.pb(u);
        for(auto v : stg[u]) vrts.pb(v);
        ans = max(ans, bck(0));
        adds.pop_back();

        // bool ok = true;
        // for(auto v1 : stg[u]) {
        //     for(auto v2 : stg[u]) {
        //         if(v1 != v2 && stg[v1].count(v2) == 0) ok = false;
        //     }
        // }
        // if(ok) ans = max(ans, gr[u]+1);

        
        for(auto v : stg[u]) {
            stg[v].erase(u);
            st.erase(mp(gr[v],v));
            --gr[v];
            st.insert(mp(gr[v],v));
        }
    }
    
    cout << ans << endl;
}

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(0);

    // freopen("in.in", "r", stdin);
    // freopen("out.out", "w", stdout);
    int tt = 1;
    // cin >> tt;
    while(tt--) {
        solve();
    }

}

Compilation message (stderr)

politicaldevelopment.cpp: In function 'long long int bck(long long int)':
politicaldevelopment.cpp:21:10: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |     if(i == vrts.size()) return adds.size();
      |        ~~^~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 12 / 12
• Subtask 3: 23 / 23
• Subtask 4: 38 / 38
• Subtask 5: 23 / 23