Submission #799420

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
799420	2023-07-31T14:03:47 Z	NothingXD	Highway Tolls (IOI18_highway)	C++17	6 / 100	101 ms	12964 KB

highway

#include "highway.h"
#include <bits/stdc++.h>

using namespace std;

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

void debug_out(){cerr << endl;}
template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T){
	cerr << H << ' ';
	debug_out(T...);
}

#define debug(...) cerr << "(" << #__VA_ARGS__ << "): ", debug_out(__VA_ARGS__)
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define MP(x, y) make_pair(x, y)

const int maxn = 2e5 + 10;

int n, m, h[maxn], par[maxn], st[maxn], ver[maxn], tme, edge[maxn][2], cnt, sz;
vector<int> g[maxn];
bool mark[maxn];
bool bad[maxn];

void bfs(int V){
	memset(h, -1, sizeof h);
	memset(par, -1, sizeof par);
	memset(mark, true, sizeof mark);
	queue<int> q;
	q.push(V);
	tme = 0;
	h[V] = 0;
	st[V] = 0;
	par[V] = -1;
	ver[0] = V;
	while(!q.empty()){
		int v = q.front();	
		//debug(v, h[v], par[v], st[v], ver[st[v]]);
		q.pop();
		for (auto x: g[v]){
			int u = edge[x][0]^edge[x][1]^v;
			if (!bad[u] && h[u] == -1){
				h[u] = h[v] + 1;
				par[u] = x;
				st[u] = ++tme;
				ver[tme] = u;
				mark[x] = false;
				q.push(u);
			}
		}
	}
	//assert(tme == sz-1);
}

void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
	n = N;
	m = U.size();
	for (int i = 0; i < m; i++){
		edge[i][0] = U[i];
		edge[i][1] = V[i];
		g[U[i]].push_back(i);
		g[V[i]].push_back(i);
	}

	vector<int> q(m, 0);
	ll dis = ask(q);
	//debug(dis);
	int l = -1, r = n-1;
	int x = 1, y = 2;
	while(l + 1 < r){
		vector<int> q(m, 0);
		int diff = r - l;
		int mid = l + diff * x / y;
		mid = max(mid, l+1);
		mid = min(mid, r-1);
		//debug(l, r, mid);
		for (int i = 0; i <= mid; i++){
			for (auto x: g[i]){
				q[x] = 1;
			}
		}
		//for (int i = 0; i < m; i++) debug(i, q[i]);
		if (ask(q) == dis) l = mid;
		else r = mid;
	}
	for (int i = 0; i < r; i++){
		bad[i] = true;
	}
//	debug(r);
	bfs(r);
//	for (int i = 0; i < m; i++) debug(i, mark[i]);
	l = 0, r = tme+1;
	while(l + 1 < r){
		vector<int> q(m, 0);
		int mid = (l + r) >> 1;
	//	debug(mid);
		for (int i = 0; i < m; i++) q[i] = mark[i];
		for (int i = mid; i < sz; i++){
			q[par[ver[i]]] = 1;
		}
	//	for (int i = 0; i < m; i++) debug(i, q[i]);
		if (ask(q) == dis) r = mid;
		else l = mid;
	}
	int S = ver[l];
	bfs(S);
//	debug(S);
//	for (int i = 0; i < m; i++) debug(i, mark[i]);

	l = tme+1, r = 0;
	for (int i = 0; i < tme+1; i++){
	//	debug(i, ver[i], h[ver[i]] * A, dis);
		if (1ll * h[ver[i]] * A == dis){
			l = min(l, i);
			r = max(r, i);
		}
	}
	r++;
	while(l + 1 < r){
		vector<int> q(m, 0);
		int mid = (l + r) >> 1;
	//	debug(mid);
		for (int i = 0; i < m; i++) q[i] = mark[i];
		for (int i = mid; i < sz; i++){
			q[par[ver[i]]] = 1;
		}
		//for (int i = 0; i < m; i++) debug(i, q[i]);
		if (ask(q) == dis) r = mid;
		else l = mid;
	}
//	debug(ver[l]);
	answer(S, ver[l]);
}

Subtask #1
0 / 5.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	4 ms	6736 KB	Output is incorrect: {s, t} is wrong.
2	Halted	0 ms	0 KB	-

Subtask #2
0 / 7.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	4 ms	6736 KB	Output is incorrect: {s, t} is wrong.
2	Halted	0 ms	0 KB	-

Subtask #3
6.0 / 6.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	11 ms	7388 KB	Output is correct
2	Correct	21 ms	8052 KB	Output is correct
3	Correct	36 ms	8636 KB	Output is correct
4	Correct	93 ms	12876 KB	Output is correct
5	Correct	101 ms	12888 KB	Output is correct
6	Correct	75 ms	12964 KB	Output is correct
7	Correct	92 ms	12544 KB	Output is correct
8	Correct	77 ms	12936 KB	Output is correct
9	Correct	79 ms	12664 KB	Output is correct