oj.uz

Submission #804716

# Submission time Handle Problem Language Result Execution time Memory
804716 2023-08-03T10:59:28 Z IvanJ Highway Tolls (IOI18_highway) C++17
7 / 100
 178 ms 15228 KB 
#include "highway.h"
#include<bits/stdc++.h>

#define pb push_back
#define x first
#define y second
#define all(a) (a).begin(), (a).end()

using namespace std;

typedef long long ll;
typedef pair<int, int> ii;

const int maxn = 2e5 + 5;

int n, m, len, A, B, pos;
vector<ii> E;
int dist[2][maxn];
int vis[maxn];
vector<ii> adj[maxn];

int get_len() {
	vector<int> w(m, 0);
	ll l = ask(w);
	return (l / A);
}

void bfs(int x, int f) {
	for(int i = 0;i < n;i++) 
		dist[f][i] = 1e9;
	dist[f][x] = 0;
	queue<int> q;
	q.push(x);
	while(q.size()) {
		x = q.front();q.pop();
		for(ii p : adj[x]) {
			if(dist[f][p.x] != 1e9) continue;
			dist[f][p.x] = dist[f][x] + 1;
			q.push(p.x);
		}
	}
}

vector<int> get_tree(int X, int f) {
	queue<int> q;
	q.push(X), vis[X] = 1;
	vector<int> ret;
	while(q.size()) {
		int x = q.front();q.pop();
		for(ii p : adj[x]) {
			if(dist[f][p.x] >= dist[!f][p.x]) continue;
			if(vis[p.x]) continue;
			vis[p.x] = 1;
			ret.pb(p.y), q.push(p.x);
		}
	}
	return ret;
}

int get_first() {
	int lo = 0, hi = m - 1, ans = -1;
	while(lo <= hi) {
		int mid = (lo + hi) / 2;
		vector<int> w(m, 0);
		for(int i = 0;i <= mid;i++) w[i] = 1;
		ll ret = ask(w);
		if(ret == (ll)len * A) lo = mid + 1;
		else ans = mid, hi = mid - 1;
	}
	return ans;
}

int get_last(vector<int> a, vector<int> b) {
	if(a.size() == 0) return -1;
	int lo = 0, hi = (int)a.size() - 1, ans = -1;
	while(lo <= hi) {
		int mid = (lo + hi) / 2;
		vector<int> w(m, 1);
		for(int i = 0;i <= mid;i++) w[a[i]] = 0;
		for(int i : b) w[i] = 0;
		w[pos] = 0;
		ll ret = ask(w);
		if(ret == (ll)len * A) 
			ans = mid, hi = mid - 1;
		else lo = mid + 1;
	}
	if(ans == -1) return -1;
	return a[ans];
}

void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
	::A = A, ::B = B;
	n = N, m = (int)U.size();
	for(int i = 0;i < m;i++) {
		E.pb({U[i], V[i]});
		adj[U[i]].pb({V[i], i}), adj[V[i]].pb({U[i], i});
	}
	len = get_len();
	
	pos = get_first();
	ii e = E[pos];
	bfs(e.x, 0);
	bfs(e.y, 1);
	
	vector<int> a = get_tree(e.x, 0);
	vector<int> b = get_tree(e.y, 1);
	int x = get_last(a, b);
	int y = get_last(b, a);
	
	int s, t;
	if(x == -1) s = e.x;
	else {
		if(dist[0][E[x].x] > dist[0][E[x].y])
			s = E[x].x;
		else s = E[x].y;
	}
	
	if(y == -1) t = e.y;
	else {
		if(dist[1][E[y].x] > dist[1][E[y].y])
			t = E[y].x;
		else t = E[y].y;
	}
	answer(s, t);
}

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 4944 KB Output is incorrect: {s, t} is wrong.
2 Halted 0 ms 0 KB -

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5072 KB Output is correct
2 Correct 10 ms 5804 KB Output is correct
3 Correct 104 ms 13244 KB Output is correct
4 Correct 116 ms 13208 KB Output is correct
5 Correct 96 ms 13216 KB Output is correct
6 Correct 101 ms 13340 KB Output is correct
7 Correct 99 ms 13212 KB Output is correct
8 Correct 116 ms 13224 KB Output is correct
9 Correct 100 ms 13224 KB Output is correct
10 Correct 111 ms 13232 KB Output is correct
11 Correct 91 ms 12276 KB Output is correct
12 Correct 89 ms 12248 KB Output is correct
13 Correct 116 ms 12656 KB Output is correct
14 Correct 114 ms 12304 KB Output is correct

Subtask #3
0 / 6.0

# Verdict Execution time Memory Grader output
1 Incorrect 10 ms 5716 KB Output is incorrect: {s, t} is wrong.
2 Halted 0 ms 0 KB -

Subtask #4
0 / 33.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 4976 KB Output is incorrect: {s, t} is wrong.
2 Halted 0 ms 0 KB -

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 5936 KB Output is correct
2 Correct 12 ms 5960 KB Output is correct
3 Correct 118 ms 13676 KB Output is correct
4 Correct 155 ms 13756 KB Output is correct
5 Correct 178 ms 15228 KB Output is correct
6 Correct 155 ms 14732 KB Output is correct
7 Correct 141 ms 14872 KB Output is correct
8 Incorrect 112 ms 14768 KB Output is incorrect: {s, t} is wrong.
9 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 5952 KB Output is correct
2 Correct 15 ms 6020 KB Output is correct
3 Correct 99 ms 13292 KB Output is correct
4 Correct 110 ms 13568 KB Output is correct
5 Correct 143 ms 13768 KB Output is correct
6 Incorrect 175 ms 14800 KB Output is incorrect: {s, t} is wrong.
7 Halted 0 ms 0 KB -