Submission #433663

#	Time	Username	Problem	Language	Result	Execution time	Memory
433663		AugustinasJucas	Highway Tolls (IOI18_highway)	C++14	12 / 100	287 ms	262148 KiB

highway

#include "highway.h"
#include <bits/stdc++.h>
using namespace std;
const int dydis = 1e5 + 10;
vector<pair<int, int> > gr[dydis];
int n, m;
long long light, heavy;
int tevas[dydis];
int dist[dydis];
int virs[dydis];
int getLen(){
	vector<int> st;
	for(int i = 0; i < m; i++) st.push_back(0);
	return 1ll * ask(st) / light;
}
void dfs(int v, int came = -1, int dst = 0){
	dist[v] = dst;
	for(auto x : gr[v]){
		if(x.first == came) continue;
		tevas[x.first] = v;
		virs[x.first] = x.second;
		dfs(x.first, v, dst+1);
	}
}
vector<pair<int, int> > getInds(int v, int len){ // first - brianos indeksas, sec - virsunes
	dfs(v, -1);
	vector<pair<int, int> > ret;
	for(int i = 0; i < n; i++){
		if(dist[i] != len) continue;
		ret.push_back({virs[i], i});
	}
	return ret;
}
pair<int, int> solveWhenHave(int v, int len){
	vector<pair<int, int> > inds = getInds(v, len); // cia turetu visi buti blogi, isskyrus viena!
	int l = 0; int r = inds.size()-1; int mid = -1; int kair = inds.size()-1;
	vector<int> askk(m, 0);
	long long turi = len * light;
	while(l <= r){
		mid = (l + r) / 2;
		for(int i = 0; i <= mid; i++) askk[inds[i].first] = 1;
		if(ask(askk) != turi){
			r = mid-1;
			kair = min(kair, mid);
		}else{
			l = mid+1;
		}
		for(int i = 0; i <= mid; i++) askk[inds[i].first] = 0;
	}
	return {v, inds[kair].second};
}
void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
	n = N;
	m = V.size();
	light = A; heavy = B;
	for(int i = 0; i < m; i++){
		gr[U[i]].push_back({V[i], i});
		gr[V[i]].push_back({U[i], i});
	}
	int len = getLen();
	auto ans = solveWhenHave(0, len);
	answer(ans.first, ans.second);
	return ;
	
}
/*

12 11 5 7 0 10
0 2
0 3
2 4
2 5
3 6
3 7
4 8
5 9
8 10
8 11
9 1

*/

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