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Submission #830823

# Submission time Handle Problem Language Result Execution time Memory
830823 2023-08-19T11:01:24 Z tranxuanbach Highway Tolls (IOI18_highway) C++17
51 / 100
 149 ms 14768 KB 
#include "highway.h"

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

#define isz(a) ((signed)a.size())

using ll = long long;

struct edge_t{
	int u, v;
};

const int N = 90'000 + 5, M = 130'000 + 5;

int n, m;
int a, b;
vector <edge_t> edge;
vector <int> adj[N];

vector <int> vquery;

namespace subtask1234{
	bool check(){
		return m == n - 1;
	}

	int length_path;

	int pv[N];
	int pe[N];
	int ctrtour, tour[N];

	void dfs_tour(int u){
		tour[ctrtour] = u;
		ctrtour++;
		for (auto i: adj[u]){
			if (i == pe[u]){
				continue;
			}
			auto v = u ^ edge[i].u ^ edge[i].v;
			pv[v] = u;
			pe[v] = i;
			dfs_tour(v);
		}
	}

	int solve_fixed(int s){
		pv[s] = -1;
		pe[s] = -1;
		ctrtour = 0;
		dfs_tour(s);

		int lo = 1, hi = n - 1;
		while (lo < hi){
			int mid = (lo + hi) >> 1;
			fill(vquery.begin(), vquery.end(), 0);
			for (int pos = 1; pos <= mid; pos++){
				vquery[pe[tour[pos]]] = 1;
			}
			if (ask(vquery) == (ll)length_path * b){
				hi = mid;
			}
			else{
				lo = mid + 1;
			}
		}
		return tour[lo];
	}

	int depth[N];

	void dfs_depth(int u){
		for (auto i: adj[u]){
			if (i == pe[u]){
				continue;
			}
			int v = u ^ edge[i].u ^ edge[i].v;
			pv[v] = u;
			pe[v] = i;
			depth[v] = depth[u] + 1;
			dfs_depth(v);
		}
	}

	int find_one(){
		int root = 1;
		pv[root] = -1;
		pe[root] = -1;
		depth[root] = 0;
		dfs_depth(root);

		int lo = 1, hi = *max_element(depth, depth + n);
		while (lo < hi){
			int mid = (lo + hi + 1) >> 1;
			fill(vquery.begin(), vquery.end(), 0);
			for (int u = 0; u < n; u++){
				if (depth[u] >= mid){
					vquery[pe[u]] = 1;
				}
			}
			if (ask(vquery) == (ll)length_path * a){
				hi = mid - 1;
			}
			else{
				lo = mid;
			}
		}
		vector <int> layer;
		for (int u = 0; u < n; u++){
			if (depth[u] == lo){
				layer.emplace_back(u);
			}
		}
		lo = 0; hi = isz(layer) - 1;
		while (lo < hi){
			int mid = (lo + hi) >> 1;
			fill(vquery.begin(), vquery.end(), 0);
			for (int i = 0; i <= mid; i++){
				vquery[pe[layer[i]]] = 1;
			}
			if (ask(vquery) == (ll)length_path * a){
				lo = mid + 1;
			}
			else{
				hi = mid;
			}
		}
		return layer[lo];
	}

	void solve(){
		fill(vquery.begin(), vquery.end(), 0);
		length_path = ask(vquery) / a;
		int s = find_one();
		int t = solve_fixed(s);
		answer(s, t);
	}
}

void find_pair(int _n, vector <int> _u, vector <int> _v, int _a, int _b){
	n = _n;
	m = isz(_u);
	edge.resize(m);
	for (int i = 0; i < m; i++){
		int u = _u[i], v = _v[i];
		edge[i] = edge_t{u, v};
		adj[u].emplace_back(i);
		adj[v].emplace_back(i);
	}
	a = _a;
	b = _b;
	vquery.resize(m);

	if (subtask1234::check()){
		subtask1234::solve();
		return;
	}
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2384 KB Output is correct
2 Correct 1 ms 2384 KB Output is correct
3 Correct 1 ms 2384 KB Output is correct
4 Correct 1 ms 2420 KB Output is correct
5 Correct 1 ms 2384 KB Output is correct
6 Correct 2 ms 2384 KB Output is correct
7 Correct 1 ms 2432 KB Output is correct
8 Correct 1 ms 2384 KB Output is correct
9 Correct 2 ms 2384 KB Output is correct
10 Correct 1 ms 2384 KB Output is correct
11 Correct 1 ms 2428 KB Output is correct
12 Correct 1 ms 2384 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2384 KB Output is correct
2 Correct 9 ms 3160 KB Output is correct
3 Correct 110 ms 9324 KB Output is correct
4 Correct 97 ms 9316 KB Output is correct
5 Correct 110 ms 9340 KB Output is correct
6 Correct 121 ms 9244 KB Output is correct
7 Correct 100 ms 9316 KB Output is correct
8 Correct 79 ms 9320 KB Output is correct
9 Correct 95 ms 9312 KB Output is correct
10 Correct 103 ms 9212 KB Output is correct
11 Correct 114 ms 10664 KB Output is correct
12 Correct 106 ms 11256 KB Output is correct
13 Correct 98 ms 10772 KB Output is correct
14 Correct 117 ms 10708 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 3792 KB Output is correct
2 Correct 13 ms 5156 KB Output is correct
3 Correct 31 ms 6488 KB Output is correct
4 Correct 82 ms 14704 KB Output is correct
5 Correct 82 ms 14684 KB Output is correct
6 Correct 83 ms 14736 KB Output is correct
7 Correct 149 ms 14768 KB Output is correct
8 Correct 77 ms 14740 KB Output is correct
9 Correct 78 ms 14640 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2384 KB Output is correct
2 Correct 8 ms 3152 KB Output is correct
3 Correct 68 ms 7792 KB Output is correct
4 Correct 99 ms 9256 KB Output is correct
5 Correct 90 ms 9328 KB Output is correct
6 Correct 73 ms 9212 KB Output is correct
7 Correct 99 ms 9232 KB Output is correct
8 Correct 114 ms 9328 KB Output is correct
9 Correct 132 ms 9312 KB Output is correct
10 Correct 94 ms 9320 KB Output is correct
11 Correct 111 ms 10332 KB Output is correct
12 Correct 106 ms 10988 KB Output is correct
13 Correct 132 ms 10728 KB Output is correct
14 Correct 143 ms 11120 KB Output is correct
15 Correct 94 ms 9212 KB Output is correct
16 Correct 68 ms 9220 KB Output is correct
17 Correct 98 ms 10428 KB Output is correct
18 Correct 100 ms 10920 KB Output is correct
19 Correct 86 ms 9260 KB Output is correct
20 Correct 132 ms 11588 KB Output is correct
21 Correct 81 ms 9868 KB Output is correct
22 Correct 76 ms 9868 KB Output is correct
23 Correct 100 ms 9784 KB Output is correct
24 Correct 110 ms 10180 KB Output is correct
25 Correct 130 ms 14220 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Incorrect 6 ms 3024 KB Output is incorrect: answered not exactly once.
2 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# Verdict Execution time Memory Grader output
1 Incorrect 8 ms 3016 KB Output is incorrect: answered not exactly once.
2 Halted 0 ms 0 KB -