Submission #765326

#	Time	Username	Problem	Language	Result	Execution time	Memory
765326		vjudge1	Roadside Advertisements (NOI17_roadsideadverts)	C++17	100 / 100	45 ms	15392 KiB

roadsideadverts

#include <bits/stdc++.h>
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("Ofast,unroll-loops,fast-math,O3")
#define ent '\n'
#define f first
#define s second

using namespace std;
typedef long long ll;
typedef pair < int, int> pii;
typedef pair < ll, ll > pll;

const int maxn = 2e5 + 100;
const int mod = 1e9 + 7;
const int INF = 1e9;
const int LOG = 20;
const int K = 400;
const int P = 31;

int n, m;
vector < pii > g[maxn];
int pref[maxn], p[LOG][maxn], tin[maxn], tout[maxn], timer, depth[maxn], a[6];
ll ans = 0;
void dfs(int v){
    for(int i = 1;i < LOG;i++){
        p[i][v] = p[i - 1][p[i - 1][v]];
    }
    tin[v] = ++timer;
    for(auto to: g[v]){
        if(to.f == p[0][v])continue;
        p[0][to.f] = v;
        depth[to.f] = depth[v] + 1;
        pref[to.f] = pref[v] + to.s;
        dfs(to.f);
    }
    tout[v] = ++timer;
}

bool upper(int a, int b){return tin[a] <= tin[b] && tout[a] >= tout[b];}

int lca(int a, int b){
    if(upper(a, b))return a;
    if(upper(b, a))return b;
    for(int i = LOG - 1;i >= 0;i--){
        if(!upper(p[i][a], b) && p[i][a] != 0)a = p[i][a];
    }
    return p[0][a];
}

void solve(){
    cin >> n;
    for(int i = 1;i < n;i++){
        int u, v, w;
        cin >> u >> v >> w;
        u++, v++;
        g[u].push_back({v, w});
        g[v].push_back({u, w});
    }
    dfs(1);
    cin >> m;
    for(int i = 1;i <= m;i++){
        cin >> a[1];
        int LCA = a[1] + 1, ans = 0;
        for(int j = 2;j <= 5;j++){
            cin >> a[j];
            LCA = lca(LCA, a[j] + 1);
        }
        for(int j = 1;j <= 5;j++){
            int q = LCA;
            for(int k = 1;k < j;k++){
                int w = lca(a[j] + 1, a[k] + 1);
                if(depth[q] < depth[w]){
                    q = w;
                }
            }
            ans += pref[a[j] + 1] - pref[q];
        }
        cout << ans << ent;
    }
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int T = 1;
    // cin >> T;
    for(int i = 1;i <= T;i++){
        solve();
    }
}

• Subtask 1: 7 / 7
• Subtask 2: 23 / 23
• Subtask 3: 40 / 40
• Subtask 4: 30 / 30