Submission #1249184

#	Time	Username	Problem	Language	Result	Execution time	Memory
1249184		al95ireyiz	Logičari (COCI21_logicari)	C++20	20 / 110	1094 ms	5704 KiB

Main

//*** Bismillah ***//
#pragma GCC optimize("O3", "fast-math", "unroll-loops", "no-stack-protector")
#include <bits/stdc++.h>
using namespace std;
#if !defined(ONLINE_JUDGE) and !defined(EVAL)
#include "template/debug.h"
#else
#define d(x...)
#endif
#define fr first
#define er erase
#define sc second
#define in insert
#define ll long long
#define pb push_back
#define vll vector<ll>
#define pll pair<ll,ll>
#define ull unsigned ll
#define vpll vector<pll>
#define len(x) (ll) x.size()
#define all(x) x.begin(),x.end()
const ll INF = 1e9;
const ll INFL = 1e18;
const ll MOD = 1e9+7;
// const ll MOD = 998244353;
const ll maxn = 1e5+5;
ll n,m,k=0;
vll g[maxn];
bool vis[maxn];
ll spec, root, dp[maxn][2][2][2][2];
void dfs(ll u, ll p = -1){
    vis[u] = 1;
    for(auto v : g[u]){
        if(v == p) continue;
        if(vis[v]){
            root = v;
            spec = u;
            return;
        }
        dfs(v, u);
        if(root != 0) return;
    }
}
#define dpp dp[u][c][up][rt][sp]
ll get(ll u, ll c, ll up, ll rt, ll sp, ll p = -1){
    if(u == spec and c != sp) return dpp = INF;
    if(u == root and c != rt) return dpp = INF;
    if(up == 1 and u == root and sp) return dpp = INF;
    if(up == 1 and u == spec and rt) return dpp = INF;
    if(dpp != INF) return dpp;
    ll cm = c;
    for(auto v : g[u]){
        if(v == p) continue;
        cm += get(v, 0, c, rt, sp, u);
    }
    if(up or (u == root and sp) or (u == spec and rt)){
        return dpp = cm;
    }
    else{
        ll cv = INF;
        for(auto v : g[u]){
            if(v == p) continue;
            cv = min(cv,
                    cm - get(v, 0, c, rt, sp, u) + get(v, 1, c, rt, sp, u));
        }
        return dpp = cv;
    }
}
void _(ll &tt){
    cin >> n;
    for(ll i = 1, a, b; i <= n; i ++){
        cin >> a >> b;
        g[a].pb(b);
        g[b].pb(a);
    }
    ll leaf = -1;
    for(ll i = 1; i <= n; i ++) if(len(g[i]) == 1){ leaf = i; break; }
    if(leaf == -1){
        cout << (n % 4 == 0 ? n / 2 : -1) << '\n';
        return;
    }
    dfs(1);
    g[root].erase(find(all(g[root]), spec));
    g[spec].erase(find(all(g[spec]), root));
    d(spec, root);
    for(ll i = 1; i <= n; i ++){
        for(auto j : {0, 1}) for(auto q : {0, 1}) for(auto l : {0, 1}) for(auto p : {0, 1}){
            dp[i][j][q][l][p] = INF; // yea, ik
        }
    }
    ll cv = INF;
    for(auto i : {0, 1}) for(auto j : {0, 1}){
        cv = min(cv, get(root, i, 0, i, j));
    }
    cout << (cv == INF ? -1 : cv) << '\n';
}
signed main() {
    ll tm = clock();
    cin.tie(0)->sync_with_stdio(0);
    ll t = 1;
    // cin >> t;
    for(ll tt = 1; tt <= t; tt ++) {
        _(tt);
    }
    cerr << "\n\033[1;31mTime: \033[1;30m" \
         << (double)(clock()-tm)/1000000 << "\033[1;32m seconds\n";
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 40
• Subtask 4: 0 / 50