Submission #931170

#	Time	Username	Problem	Language	Result	Execution time	Memory
931170		Whisper	Putovanje (COCI20_putovanje)	C++17	110 / 110	95 ms	38484 KiB

putovanje

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using str = string;
using ld = long double;
using T = tuple<ll, ll, ll>;

#define int long long
#define Base 31
#define sz(a) (int)a.size()
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = a; i >= b; i --)
#define REP(i, n) for ( int i = 0 ; i < n ; ++i )
#define REPD(i, n) for ( int i =  n - 1 ; ~(--i) ; )
#define all(x) x.begin() , x.end()
#define pii pair<int , int>
#define fi first
#define se second
#define Lg(x) 31 - __builtin_clz(x)

constexpr ll LINF = (1ll << 62);
constexpr int INF = (1ll << 30);
constexpr int MAX = 2e5 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void setupIO(){
    #define name "Whisper"
    //Phu Trong from Nguyen Tat Thanh High School for gifted student
    srand(time(NULL));
    cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
    // freopen(name".inp", "r", stdin);
    // freopen(name".out", "w", stdout);
    cout << fixed << setprecision(10);
}
int n;
vector<T> adj[MAX];
const int Log = 20;
int up[MAX][Log], dep[MAX], f[MAX];
int  ans = 0;
//using f(i) as the number we come to the ith city with minimize cost
void dfs(int u, int p){
    for (auto&[v, _, __] : adj[u]) if(v ^ p){
        dep[v] = dep[u] + 1;
        up[v][0] = u;
        for (int i = 1 ; i < Log ; i++){
            up[v][i] = up[up[v][i - 1]][i - 1];
        }
        dfs(v, u);
    }
}
void Lca(int u, int v){
    f[u]++, f[v]++;
    if (dep[u] < dep[v]) swap(u, v);
    int dis = dep[u] - dep[v];
    for (; dis > 0; dis ^= (dis & (-dis))){
        int i = __builtin_ctz(dis & (-dis));
        u = up[u][i];
    }
    if (u == v){
        f[u] -= 2;
        return;
    }
    int k = Lg(dep[v]);
    for (int i = k ; i >= 0 ; i--){
        if (up[u][i] != up[v][i]){
            u = up[u][i];
            v = up[v][i];
        }
    }
    f[up[u][0]] -= 2;
}

void cal(int u, int p){
    for (auto&[v, c1, c2] : adj[u]) if(v ^ p){
        cal(v, u);
        f[u] += f[v];
        ans += min(f[v] * c1, c2);
    }
}
void Whisper(){
    cin >> n;
    for (int i = 1 ; i < n ; i++){
        int u, v, c1, c2; cin >> u >> v >> c1 >> c2;
        adj[u].push_back({v, c1, c2});
        adj[v].push_back({u, c1, c2});
    }

    dfs(1, 0);

    for(int i = 1 ; i < n ; i++){
        Lca(i, i + 1);
    }

    cal(1, 0);
    cout << ans;
}

signed main(){
    setupIO();
    int Test = 1;
    // cin >> Test;
    for ( int i = 1 ; i <= Test ; i++ ){
        Whisper();
        if (i < Test) cout << '\n';
    }
}

• Subtask 1: 20 / 20
• Subtask 2: 25 / 25
• Subtask 3: 65 / 65