제출 #1228773

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1228773		AmirAli_H1	통행료 (IOI18_highway)	C++17	100 / 100	125 ms	27924 KiB

highway

// In the name of Allah

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

typedef		long long int			ll;
typedef		long double				ld;
typedef		pair<int, int>			pii;
typedef		pair<ll, ll>			pll;
typedef		complex<ld>				cld;

#define		all(x)					(x).begin(),(x).end()
#define		len(x)					((ll) (x).size())
#define		F						first
#define		S						second
#define		pb						push_back
#define		sep						' '
#define		endl					'\n'
#define		Mp						make_pair
#define		kill(x)					cout << x << '\n', exit(0)
#define		set_dec(x)				cout << fixed << setprecision(x);
#define		file_io(x,y)			freopen(x, "r", stdin); freopen(y, "w", stdout);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int maxn = 2e5 + 4;
const int oo = 1e9 + 4;

int n, m, W0, W1; ll D; pii ans;
vector<pii> E; vector<int> Q, Qx;
vector<pii> adj[maxn], adjx[maxn];
int dis[maxn]; queue<int> qu;
int h[maxn]; pii par[maxn];
vector<int> ls;

bool cmp(int u, int v) {
	return (h[u] > h[v]);
}

bool checkx(int x) {
	for (int i = 0; i < m; i++) {
		if (i < x) Q[i] = 1;
		else Q[i] = 0;
	}
	return (ask(Q) == D);
}

bool checkf(int x) {
	Q = Qx;
	for (int i = 0; i < x; i++) {
		int j = par[ls[i]].S; Q[j] = 1;
	}
	return (ask(Q) == D);
}

void bfs(int v) {
	fill(dis, dis + n, oo);
	dis[v] = 0; qu.push(v);
	while (!qu.empty()) {
		int v = qu.front(); qu.pop();
		for (auto f : adjx[v]) {
			int u = f.F, j = f.S;
			if (dis[v] + 1 < dis[u]) {
				dis[u] = dis[v] + 1; qu.push(u);
				adj[v].pb(Mp(u, j)); adj[u].pb(Mp(v, j));
				Qx[j] = 0;
			}
		}
	}
}

void dfs(int v, int p) {
	for (auto f : adj[v]) {
		int u = f.F, j = f.S;
		if (u == p) continue;
		h[u] = h[v] + 1; par[u] = Mp(v, j); ls.pb(u);
		dfs(u, v);
	}
}

int getx() {
	int l = 0, r = len(ls) + 1;
	while (r - l > 1) {
		int mid = (l + r) / 2;
		if (checkf(mid)) l = mid;
		else r = mid;
	}
	if (l == len(ls)) return -1;
	else return ls[l];
}

void find_pair(int Nx, vector<int> Ux, vector<int> Vx, int Ax, int Bx) {
	n = Nx; m = len(Ux); W0 = Ax; W1 = Bx;
	for (int i = 0; i < m; i++) E.pb(Mp(Ux[i], Vx[i]));
	Q.resize(m); fill(all(Q), 0); D = ask(Q);
	int l = 0, r = m;
	while (r - l > 1) {
		int mid = (l + r) / 2;
		if (checkx(mid)) l = mid;
		else r = mid;
	}
	for (int i = l; i < m; i++) {
		int u = E[i].F, v = E[i].S;
		adjx[u].pb(Mp(v, i)); adjx[v].pb(Mp(u, i));
	}
	int ux = E[l].F, vx = E[l].S;
	Qx.resize(m); fill(all(Qx), 1); bfs(ux);
	ls.clear(); dfs(ux, vx); sort(all(ls), cmp);
	ans.F = getx();
	if (ans.F == -1) ans.F = ux;
	ls.clear(); dfs(vx, ux); sort(all(ls), cmp);
	ans.S = getx();
	if (ans.S == -1) ans.S = vx;
	answer(ans.F, ans.S);
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 6 / 6
• Subtask 4: 33 / 33
• Subtask 5: 18 / 18
• Subtask 6: 31 / 31