Submission #496352

#	Time	Username	Problem	Language	Result	Execution time	Memory
496352		xynex	Valley (BOI19_valley)	C++17	100 / 100	528 ms	183760 KiB

valley

/*
* Author: xynex
* Created: 21.12.2021 11:20
* Why am I so stupid? :c
* Slishkom slab
*/

#include <bits/stdc++.h>

// #pragma GCC optimize("inline")
// #pragma GCC optimize("-fgcse,-fgcse-lm")
// #pragma GCC optimize("-ftree-pre,-ftree-vrp")
// #pragma GCC optimize("-ffast-math")
// #pragma GCC optimize("-fipa-sra")
// #pragma GCC optimize("-fpeephole2")
// #pragma GCC optimize("-fsched-spec")
// #pragma GCC optimize("Ofast,no-stack-protector")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
// #pragma GCC optimize("unroll-loops")

using namespace std;

#define ll long long
#define dl double long
#define ull unsigned long long
#define pr pair
#define vt vector
#define ff first
#define ss second
#define mp make_pair
#define sz(a) (int)a.size()
#define pb push_back
#define pf push_front
#define popB pop_back
#define popF pop_front
#define bit_count __builtin_popcount
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sp(x) fixed << setprecision(x)

template<typename T> T get_rand(T l, T r) {
    random_device rd;
    mt19937 gen(rd());
    return uniform_int_distribution<T>(l, r)(gen);
}

template<typename T> T lcm(T a, T b) { return a * (b / __gcd(a, b)); }

template<class A> void read(vt<A>& v);
template<class A, size_t S> void read(array<A, S>& a);
template<class T> void read(T& x) { cin >> x; }
void read(double& d) { string t; read(t); d = stod(t); }
void read(long double& d) { string t; read(t); d = stold(t); }
template<class H, class... T> void read(H& h, T&... t) { read(h); read(t...); }
template<class A> void read(vt<A>& x) { for (auto& a : x) read(a); }
template<class A, size_t S> void read(array<A, S>& x) { for (auto& a : x) read(a); }

string to_string(char c) { return string(1, c); }
string to_string(bool b) { return b ? "true" : "false"; }
string to_string(const char* s) { return string(s); }
string to_string(string s) { return s; }
string to_string(vt<bool> v) { string res; for (int i = 0; i < sz(v); ++i) res += char('0' + v[i]); return res; }
template<size_t S> string to_string(bitset<S> b) { string res; for (int i = 0; i < S; ++i) res += char('0' + b[i]); return res; }
template<class T> string to_string(T v) { bool f = 1; string res; for (auto x : v) { if (!f) res += ' '; f = 0; res += to_string(x); } return res; }

template<class A> void write(A x) { cout << to_string(x); }
template<class H, class... T> void write(const H& h, const T&... t) { write(h); write(t...); }

void print() { write("\n"); }
template<class H, class... T> void print(const H& h, const T&... t) { write(h); if (sizeof...(t)) write(' '); print(t...); }

void freop(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

const int MOD = 1e9 + 7;
const int N = 3e6 + 5;
const ll INF = 9e18;
const int M = 3e3 + 5;
const dl pi = acos(-1);
const dl eps = 1e-12;
const int sq = 700;

int dx[] = {-1, 0, 1, 0};
int dy[] = {0, -1, 0, 1};
/* ll vs int*/

void precalc() {

}

int tin[N], tout[N], timer = 0, up[N][30], LOG, n, s, q, e;
ll dist[N], depth[N], pos[N], mn[N], add[N], ans[N];
vt<pr<int, ll> > g[N], query[N];
pr<int, pr<int, int>> all[N];
bool shop[N];
void dfs(int v, int p) {
    tin[v] = ++timer;
    pos[timer] = v;
    up[v][0] = p;
    for(int i = 1; i <= LOG; ++i) up[v][i] = up[up[v][i - 1]][i - 1];
    for(auto to : g[v]) {
        if(to.ff == p) continue;
        dist[to.ff] = dist[v] + to.ss;
        dfs(to.ff, v);
    }
    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; i >= 0; --i) {
		if(!upper(up[a][i], b)) a = up[a][i];
	}
	return up[a][0];
}
ll get_dist(int a, int b) {
    return dist[a] + dist[b] - dist[lca(a, b)] * 2;
}

void build(int l = 1, int r = n, int v = 1) {
    if(l == r) {
        mn[v] = INF;
        if(shop[pos[l]]) mn[v] = dist[pos[l]];
        return;
    }
    int mid = (r + l) >> 1;
    build(l, mid, v * 2); build(mid + 1, r, v * 2 + 1);
    mn[v] = min(mn[v * 2], mn[v * 2 + 1]);
}
void lazy(int tl, int tr, int v) {
    if(tl != tr) {
        add[v * 2] += add[v];
        add[v * 2 + 1] += add[v];
    }
    mn[v] += add[v];
    add[v] = 0;
}
void upd(int l, int r, ll ind, int tl = 1, int tr = n, int v = 1) {
    lazy(tl, tr, v);
    if(tl > r || tr < l) return;
    if(tl >= l && tr <= r) {
        add[v] += ind;
        lazy(tl, tr, v);
        return;
    }
    int mid = (tl + tr) >> 1;
    upd(l, r, ind, tl, mid, v * 2); upd(l, r, ind, mid + 1, tr, v * 2 + 1);
    mn[v] = min(mn[v * 2], mn[v * 2 + 1]);
}
ll get(int l, int r, int tl = 1, int tr = n, int v = 1) {
    lazy(tl, tr, v);
    if(tl > r || tr < l) return INF;
    if(tl >= l && tr <= r) return mn[v];
    int mid = (tl + tr) >> 1;
    return min(get(l, r, tl, mid, v * 2), get(l, r, mid + 1, tr, v * 2 + 1));
}
void go(int v, int p) {
   // print(v);
    for(auto to : query[v]) {
        int edge = to.ff;
        int pq = to.ss;
        int x = all[edge].ss.ff, y = all[edge].ss.ss, weight = all[edge].ff;
        //print(x, y, weight, get_dist(y, e), get_dist(x, v), get_dist(v, e));
        if((weight + get_dist(y, e) + get_dist(x, v)) == get_dist(v, e)) ans[pq] = get(tin[x], tout[x]);
        else if((weight + get_dist(x, e) + get_dist(y, v)) == get_dist(v, e)) ans[pq] = get(tin[y], tout[y]);
        else ans[pq] = -1;
    }
    for(auto to: g[v]) {
        if(to.ff == p) continue;
        upd(tin[to.ff], tout[to.ff], -to.ss);
        upd(1, tin[to.ff] - 1, to.ss);
        upd(tout[to.ff] + 1, n, to.ss);
        go(to.ff, v);
        upd(tin[to.ff], tout[to.ff], to.ss);
        upd(1, tin[to.ff] - 1, -to.ss);
        upd(tout[to.ff] + 1, n, -to.ss);
    }
}
void solve() {
    read(n, s, q, e);
    LOG = ceil(log2(n));
    for(int i = 0; i <= LOG; ++i) {
        for(int j = 1; j <= n; ++j) up[j][i] = -1;
    }
    int id = 1;
    for(int i = 1; i < n; ++i) {
        int l, r, w; read(l, r, w);
        all[id++] = {w, {l, r}};
        g[l].pb({r, w});
        g[r].pb({l, w});
    }
    for(int i = 1; i <= s; ++i) {
        int whr; read(whr);
        shop[whr] = 1;
    }
    for(int i = 1; i <= q; ++i) {
        int x, y; read(x, y);
        query[y].pb({x, i});
    }
    dfs(e, e);
    build();
    go(e, e);
    for(int i = 1; i <= q; ++i) {
        if(ans[i] > 1e14) print("oo");
        else if(ans[i] != -1) print(ans[i]);
        else print("escaped");
    }
}

int main() {
    //freop("");
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t = 1;
    //read(t);
    precalc();
    for (int i = 1; i <= t; ++i) {
        //write("Case #" + to_string(i) + ": ");
        solve();
    }
    return 0;
}

Compilation message (stderr)

valley.cpp: In function 'void freop(std::string)':
valley.cpp:73:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:74:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 27 / 27
• Subtask 3: 23 / 23
• Subtask 4: 41 / 41