Submission #1197053

#	Time	Username	Problem	Language	Result	Execution time	Memory
1197053		tkm_algorithms	Highway Tolls (IOI18_highway)	C++20	0 / 100	7 ms	2040 KiB

highway

/**
*    In the name of Allah
*    We are nothing and you're everything
**/
#include <bits/stdc++.h>
#include "highway.h"
using namespace std;
using ll = long long;

#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()

const char nl = '\n';

vector<int> w;
const int NN = 9e4+5;

int btree[NN];

// int ask(vector<int> w1) {
// 	int cost = 0;
// 	for (int i = 0; i < sz(w1); ++i) {
// 		if (w1[i] == 1) {
// 			if (i == 0)cost += 2;
// 		} else 
// 			if (i == 0)cost += 1;
// 	}
// 	return cost;
// }

// void answer(int x, int y) {
// 	cout << y;
// }

void find_pair(int N, vector<int> u, vector<int> v, int a, int b) {
	int m = sz(u), n = N;
	vector<pair<int, int>> g[n+1];
	w.resize(m);
	for (int i = 0; i < m; ++i) {
		g[u[i]].push_back({v[i], i});
		g[v[i]].push_back({u[i], i});
	}
	
	ll cost = ask(w), len = cost/a;
	
	queue<pair<int, int>> q; // u, and par.
	q.push({0, 0});
	
	int which = 1;
	while (!q.empty()) {
		int ux = q.front().first, p = q.front().second;
		q.pop();
		for (auto i: g[ux]) {
			if (i.first == p)continue;
			btree[which++] = i.second;
			q.push({i.first, ux});
		}
	}
	
	//int ans = -1;
	int l = 1, r = m+1;
	//cout << which << nl;
	//cout << l << " " << r << nl;
	while (r-l>1) {
		int mid = l+r>>1;
		for (int i = 1; i <= m; ++i) {
			int x = btree[i]; w[x] = 0;
			if (i >= mid)w[x] = 1;
		}
		ll d = ask(w);
		//cout << mid << " " << d << nl;
		if (d != cost)l = mid;
		else r = mid;
	}
	
	//for (int i = 0; i < m; ++i)
		//w[i] = 0;
		
	answer(0, v[btree[l]]);
}


//void solve() {
	//int n, m; cin >> n >> m;
	//vector<int> u(m), v(m);
	//for (int i = 0; i < m; ++i) {
		//cin >> u[i] >> v[i];
	//}
	
	//find_pair(n, u, v, 1, 2);
//}

//int32_t main() {
    //ios::sync_with_stdio(0);
    //cin.tie(0);
    //int t = 1;
    //for (int _ = 0; _ < t; ++_) {
        //solve();
    //}
    //return 0;
//}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 7
• Subtask 3: 0 / 6
• Subtask 4: 0 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31