Submission #765384

#	Time	Username	Problem	Language	Result	Execution time	Memory
765384		vjudge1	Roadside Advertisements (NOI17_roadsideadverts)	C++17	100 / 100	67 ms	22604 KiB

roadsideadverts

#include "bits/stdc++.h"
using namespace std;

// #define ORD_SET
// #define ROPE
#ifdef ORD_SET
    #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>;
#endif
#ifdef ROPE
    #include <ext/rope>
    using namespace __gnu_cxx;
#endif        

// #pragma comment(linker, "/stack:200000000")
// #pragma GCC optimize("Ofast")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")

using ll = long long;
using ld = long double;
#define pb push_back
#define ff first
#define ss second
#define sz(x) (ll)(x).size()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

void freopen(string s) { freopen((s+".in").c_str(), "r", stdin); freopen((s+".out").c_str(), "w", stdout); }
void ioigold2024insh() { ios_base::sync_with_stdio(false); cin.tie(NULL); }
void pre(ll a) { cout<<fixed<<setprecision(a); }
ll bit(ll a) { return __builtin_popcountll(a); }
ll binmul(ll a, ll b, ll c) { ll res = 0; while(b) { if(b&1) (res += a) %= c; (a += a) %= c; b >>= 1; } return res; }
ll binpow(ll a, ll b, ll c) { ll res = 1; while(b) { if(b&1) (res *= a) %= c; (a *= a) %= c; b >>= 1; } return res; }
template<typename T> T gcd(T a, T b) { if(b==0) return a; return gcd(b, a%b); }
template<typename T> T lcm(T a, T b) { return a/gcd(a, b)*b; }
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ld rnd() { return rng()%INT_MAX*1.0/INT_MAX; }

struct sn { ll l, r, x; };
const ll mod = 1e9+7, inf = 1e18+7, MX = LLONG_MAX, MN = LLONG_MIN;
const ll N = 3e5+5;
vector<pair<ll, ll>> g[N];
ll up[N][20], pr[N], d[N], tin[N], tout[N], timer;

void dfs(ll v, ll p) {
    up[v][0] = p;
    for(ll i=1; i<=16; i++) up[v][i] = up[up[v][i-1]][i-1];
    tin[v] = ++timer;
    for(auto [to, w]: g[v]) {
        if(to==p) continue;
        pr[to] = pr[v]+w, d[to] = d[v]+1;
        dfs(to, v);
    }
    tout[v] = ++timer;
}

ll lca(ll x, ll y) {
    if(d[x]<d[y]) swap(x, y);
    ll k = d[x]-d[y];
    for(ll i=16; i>=0; i--) {
        if(k&(1<<i)) x = up[x][i];
    }
    if(x==y) return x;
    for(ll i=16; i>=0; i--) {
        if(up[x][i]!=up[y][i]) x = up[x][i], y = up[y][i];
    }
    return up[x][0];
}

void kigash() {
    ll n;
    cin>>n;
    for(ll i=1; i<n; i++) {
        ll u, v, w;
        cin>>u>>v>>w;
        g[++u].pb({++v, w}), g[v].pb({u, w});
    }
    dfs(1, 0);
    ll q;
    cin>>q;
    for(ll t=1; t<=q; t++) {
        ll res = 0;
        vector<pair<ll, ll>> v;
        for(ll j=1; j<=5; j++) {
            ll x;
            cin>>x, x++;
            v.pb({tin[x], x});
        }
        sort(all(v));
        for(ll j=0; j<5; j++) {
            ll x = v[j].ss, y = v[(j+1)%5].ss;
            ll lc = lca(x, y);
            res += pr[x]+pr[y]-2*pr[lc];
        }
        cout<<res/2<<"\n";
    }
    return;
}

signed main(/*Kigash Amir*/) {
    // freopen("");
    ioigold2024insh();
    ll tt = 1;
    // cin>>tt;
    for(ll i=1; i<=tt; i++) kigash();
    exit(0);
}

Compilation message (stderr)

roadsideadverts.cpp: In function 'void freopen(std::string)':
roadsideadverts.cpp:31:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 | void freopen(string s) { freopen((s+".in").c_str(), "r", stdin); freopen((s+".out").c_str(), "w", stdout); }
      |                          ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
roadsideadverts.cpp:31:73: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 | void freopen(string s) { freopen((s+".in").c_str(), "r", stdin); freopen((s+".out").c_str(), "w", stdout); }
      |                                                                  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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