Submission #741924

#	Time	Username	Problem	Language	Result	Execution time	Memory
741924		Filya	Logičari (COCI21_logicari)	C++14	10 / 110	182 ms	45756 KiB

Main

/////////////////////include/////////////////////
//#include <bits/stdc++.h>
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <string>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <cassert>
#include <set>
#include <map>
#include <unordered_map>
#include <vector>
#include <stack>
#include <queue>
#include <iomanip>
#include <bitset>
#include <stdio.h>
#include <climits>
#include <numeric>
using namespace std;
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//using namespace __gnu_pbds;
//template <typename T>
//using ordered_set = tree <T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
/////////////////////define/////////////////////
#define ci(x) if(x) cout << "YES" << '\n'; else cout << "NO" << '\n';
#define cii(x) if(check(x))
#define MOD 1000000007
#define MOD2 998244353
#define oo 1e9
#define ool 1e18L
#define pii pair<int, int>
#define pll pair<long long, long long>
#define mii map<int, int>
#define vi vector<int>
#define vpi vector<pair<int, int>>
#define vll vector <ll>
#define ff first
#define ss second
#define mp make_pair
#define ll long long
#define ld long double
#define pb push_back
#define eb emplace_back
#define pob pop_back
#define lb lower_bound
#define ub upper_bound
#define bs binary_search
#define sz(x) (int((x).size()))
#define all(x) (x).begin(), (x).end()
#define alll(x) (x), (x) + n
#define clr(x) (x).clear();
#define fri(x) for(int i = 0; i < x; ++i)
#define frj(x) for(int j = 0; j < x; ++j)
#define frp(x) for(int p = 0; p < x; ++p)
#define frr(a, b) for(int i = a; i < b; ++i)
#define frrj(a, b) for(int j = a; j < b; ++j)
#define fra(x) for(int i = 0; i < x; ++i) cin >> a[i];
#define frb(x) for(int i = 0; i < x; ++i) cin >> b[i];
#define frs(x) for(auto it = x.begin(); it != x.end(); ++it)
#define fr(x) for(auto it : x) //el
#define fastio ios_base::sync_with_stdio(false); cin.tie(0);
#define dbg(x) cerr << #x << ": " << x << endl;
#define ce(x) cout << x << endl;
#define uniq(x) x.resize(unique(all(x)) - x.begin()); //make all one after sorting
#define blt __builtin_popcount
/////////////////////print array, vector, deque, set, multiset, pair, map /////////////////////
void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(long double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T, class V> void print(T v[],V n) {cerr << "["; for(int i = 0; i < n; i++) {print(v[i]); cerr << " "; } cerr << "]"; cout << endl;}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]"; cout << endl;}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]"; cout << endl;}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]"; cout << endl;}
template <class T> void print(stack <T> v) {cerr << "[ "; stack<T> s = v; while(s.size()) {T i = s.top(); print(i); s.pop(); cerr << " ";} cerr << "]"; cout << endl;}
template <class T> void print(queue <T> v) {cerr << "[ "; queue<T> s = v; while(s.size()) {T i = s.front(); print(i); s.pop(); cerr << " ";} cerr << "]"; cout << endl;}
template <class T> void print(deque <T> v) {cerr << "[ "; deque<T> s = v; while(s.size()) {T i = s.front(); print(i); s.pop_front(); cerr << " ";} cerr << "]"; cout << endl;}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]"; cout << endl;}
template <class T, class V> void print(unordered_map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]"; cout << endl;}
/////////////////////code/////////////////////
vi t[100005];
int dp[100005][2][2][2][2], root, special; //ira guyn, parenti guyn, rooti, speciali
bool dfs(int v, int p) {
    int cnt = 0;
    bool f = 0;
    for(int u : t[v]) {
        if(u == p) continue;
        f |= dfs(u, v);
        cnt++;
    }
    fri(2) {
        frj(2) {
            for(int rc = 0; rc < 2; rc++) {
                for(int sc = 0; sc < 2; sc++) {
                    if((v==root && i != rc) || 
                       (v==special && i != sc) || 
                       (p==root && j != rc) || 
                       (p==special && j != sc) ||
                       (v==special && rc && j) || 
                       (!cnt && !j && !(v == special && rc)) ||
                       (v==root && j) || 
                       (p == root && i && sc) || 
                       (p == special && i && rc)
                       )
                    {
                        dp[v][i][j][rc][sc] = -1;
                    }
                    else {
                        // if(v==1) { dbg(i) dbg(j) dbg(rc) dbg(sc) }
                        if(j || (v==root && sc) || (v==special && rc)) { //ira erexeqi guyn 0
                            dp[v][i][j][rc][sc] = i;
                            for(int u : t[v]) {
                                if(u == p) continue;
                                if(dp[u][0][i][rc][sc] == -1) {
                                    dp[v][i][j][rc][sc] = -1;
                                    break;
                                } 
                                else dp[v][i][j][rc][sc] += dp[u][0][i][rc][sc];
                            }
                        } else { //erexeqic uxix 1y pti 1lini
                            vi anhnarner;
                            dp[v][i][j][rc][sc] = i;
                            for(int u : t[v]) {
                                if(u == p) continue;
                                if(dp[u][0][i][rc][sc] == -1) 
                                    anhnarner.pb(u);
                                else dp[v][i][j][rc][sc] += dp[u][0][i][rc][sc];
                            }
                            if(anhnarner.size() >= 2) dp[v][i][j][rc][sc] = -1;
                            else if(anhnarner.size() == 1) {
                                if(dp[anhnarner[0]][1][i][rc][sc] != -1)
                                    dp[v][i][j][rc][sc] += dp[anhnarner[0]][1][i][rc][sc];
                                else dp[v][i][j][rc][sc] = -1;
                            } else {
                                int cur = dp[v][i][j][rc][sc];
                                dp[v][i][j][rc][sc] = 1e9;
                                for(int u : t[v]) {
                                    if(u == p || dp[u][1][i][rc][sc] == -1) continue;
                                    dp[v][i][j][rc][sc] = min(dp[v][i][j][rc][sc], 
                                    cur - dp[u][0][i][rc][sc] + dp[u][1][i][rc][sc]);
                                }
                                if(dp[v][i][j][rc][sc] == 1e9) dp[v][i][j][rc][sc] = -1;
                            }
                        }
                    }
                }
            }
        }
    }
    // dbg(v) dbg(cnt)
    if(!cnt)
        return 1;
    return 0;
}
 
vi g[100005];
vi cycle;
int vis[100005], f; 
int p[100005];
void find_cycle(int v, int par) {
    vis[v] = 1;
    p[v] = par;
    for(int u : g[v]) {
        if(u == par) continue;
        if(vis[u] == 1) {
            int cur = v;
            while(cur != u) {
                cycle.pb(cur);
                if(cur == p[cur]) assert(0);
                cur = p[cur];
            }
            cycle.pb(cur);
            f = 1;
            return;
        }
        else if(!vis[u])
            find_cycle(u, v);
        if(f) return;
    }
    vis[v] = 2;
}
 
int x[100005], y[100005];
int main() {
    fastio;
    int n; cin >> n;
    fri(n) {
        cin >> x[i] >> y[i];
        g[x[i]].pb(y[i]);
        g[y[i]].pb(x[i]);
    }
    find_cycle(1, 1);
    assert(cycle.size() > 2);
    root = cycle[0], special = cycle[1];
    fri(n) {
        if(root==x[i]&&special==y[i]) continue;
        if(special==x[i]&&root==y[i]) continue;
        t[x[i]].pb(y[i]);
        t[y[i]].pb(x[i]);
    }
    // frr(1, 1 + n) print(t[i]);
    // dbg(root) dbg(special)
    dfs(root, root);
    // for(int v = 1; v <= n; v++) {
    //     dbg(v) 
    //     fri(2) {
    //         frj(2) {
    //             for(int rc = 0; rc < 2; rc++) {
    //                 for(int sc = 0; sc < 2; sc++) {
    //                     if(dp[v][i][j][rc][sc] == -1) continue;
    //                     dbg(i) dbg(j) dbg(rc) dbg(sc) dbg(dp[v][i][j][rc][sc])
    //                 }
    //             }
    //         }
    //     }
    // }
    int ans = 1e9;
    fri(2) {
        frj(2) {
            for(int rc = 0; rc < 2; rc++) {
                for(int sc = 0; sc < 2; sc++) {
                    if(dp[root][i][j][rc][sc] != -1)
                        ans = min(ans, dp[root][i][j][rc][sc]);
                }
            }
        }
    }
    if(ans == 1e9) ans = -1;
    cout << ans;
    return 0;
}
 
//	           ♥ ♥ ♥  ♥  ♥    ♥   ♥    ♥
//	           ♥      ♥  ♥     ♥ ♥    ♥ ♥
//	           ♥ ♥ ♥  ♥  ♥      ♥    ♥   ♥
//	           ♥      ♥  ♥      ♥   ♥ ♥ ♥ ♥
//	           ♥      ♥  ♥ ♥ ♥  ♥  ♥       ♥
//
//        God loves Fil, Fil accepts God's will

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