Submission #1032287

#	Time	Username	Problem	Language	Result	Execution time	Memory
1032287		Whisper	Logičari (COCI21_logicari)	C++17	0 / 110	6 ms	16216 KiB

Main

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

#define int long long
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FORD(i, a, b) for (int i = (b); i >= (a); i --)
#define REP(i, a) for (int i = 0; i < (a); ++i)
#define REPD(i, a) for (int i = (a) - 1; i >= 0; --i)

#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)


constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

/*
    Phu Trong from Nguyen Tat Thanh High School for gifted student
*/

template <class X, class Y>
    bool minimize(X &x, const Y &y){
        X eps = 1e-9;
        if (x > y + eps) {x = y; return 1;}
        return 0;
    }

template <class X, class Y>
    bool maximize(X &x, const Y &y){
        X eps = 1e-9;
        if (x + eps < y) {x = y; return 1;}
        return 0;
    }
#define MAX         100005
int numNode;

vector<int> G[MAX];

//dp(u, me, pa, root, special)

int vis[MAX];
int special = -1, root = -1;
void pre_dfs(int u, int p = -1){
    vis[u] = 1;
    for (int &v : G[u]) if(v ^ p){
        if(vis[v]){
            special = v, root = u;
        }
        if(!vis[v])
            pre_dfs(v, u);
    }
}
int dp[MAX][2][2][2][2];
bool bad(int u, int self, int pa, int rt, int sc){
    if (u == root && self != rt) return true;
    if (u == special && self != sc) return true;
    if (u == special && (pa & root) == 1) return true;
    return false;
}

bool check (int u, int v){
    return ((u != special && v != special) || (u != root && v != root));
}
int F(int u, int p, int self, int pa, int rt, int sc){
    int &ret = dp[u][self][pa][rt][sc];
    if(~ret) return ret;
    ret = INF;
    if (bad(u, self, pa, rt, sc)) {
        return ret;
    }
    bool must = 0;
    must |= pa;
    must |= (u == special && root == 1);
    must |= (u == root && special == 1);

    int sm = 0;
    if (self) ++sm;
    for (int&v : G[u]) if(v ^ p){
        if(!check(u, v)) continue;
        sm += F(v, u, 0, self, rt, sc);
    }

    if (must){
        minimize(ret, sm);
    }

    if (!must){
        for (int &v : G[u]) if(v ^ p){
            if(!check(u, v)) continue;
            int cur = sm - F(v, u, 0, self, rt, sc) + F(v, u, 1, self, rt, sc);
            minimize(ret, cur);
        }
    }
    if (ret > INF) ret = INF;
    return ret;
}
void process(void){
    cin >> numNode;
    for (int i = 1; i <= numNode; ++i){
        int u, v; cin >> u >> v;
        G[u].emplace_back(v);
        G[v].emplace_back(u);
    }
    pre_dfs(1);

    int ans = INF;
    REP(i, 2) REP(j, 2){
        memset(dp, -1, sizeof dp);
        minimize(ans, F(root, 0, i, 0, i, j));
    }
    if(ans == INF) ans = -1;
    cout << ans;
}
signed main(){
    #define name "Whisper"
    cin.tie(nullptr) -> sync_with_stdio(false);
    //freopen(name".inp", "r", stdin);
    //freopen(name".out", "w", stdout);
    process();
    return (0 ^ 0);
}

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