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Submission #139124

# Submission time Handle Problem Language Result Execution time Memory
139124 2019-07-31T09:44:53 Z MAMBA Highway Tolls (IOI18_highway) C++17
51 / 100
 298 ms 9672 KB 
#include "highway.h"
#include <bits/stdc++.h>

using namespace std;

#define rep(i , j , k) for(int i = j; i < (int)k; i++)
#define all(x) x.begin(),x.end()
#define pb push_back

inline bool smin(int &a , int b) { return b < a ? a = b , true : false; }

typedef vector<int> vi;
typedef long long ll;

void find_pair(int N,  vi U, vi V, int A, int B) {
	int M = U.size();

	vector<vi> adj(N);
	rep(i , 0 , M) {
		adj[U[i]].pb(i);
		adj[V[i]].pb(i);
	}

	// faze 1 : peyda kardan fasele 
	int len = ask(vi(M)) / A;

	// faze 2 : peyda kardane ye yal to masir

	int lovelyEdge = -1;

	{
		int lo = -1 , hi = M - 1;
		while (lo != hi - 1) {
			int mid = lo + hi >> 1;
			vi local(mid + 1 , 1);
			local.resize(M);

			if (ask(local) != 1ll * A * len)
				hi = mid;
			else 
				lo = mid;
		}
		lovelyEdge = hi;
	}


	// faze 3 : peyda kardane rasaye chap va rasaye rast va sakhtane deralht chap o rast :

	vector<bool> active(N , true);
	vi d1(N) , d2(N), d3(N);
	vi edge1, edge2;
	auto bfs = [&](int v , vi &d, vi& edge) {

		edge.clear();
		edge.pb(lovelyEdge);
		fill(all(d) , 1e9);
		vi q(N);
		int L = 0 , R = 0;

		assert(active[v]);
		d[v] = 0;
		q[R++] = v;
		while (L < R) {
			v = q[L++];		
			for (auto e : adj[v]) {
				int u = V[e] ^ U[e] ^ v;
				if (!active[u]) continue;
				if (smin(d[u] , d[v] + 1)) 
					q[R++] = u;

				if (d[u] == d[v] + 1) {
					if (V[e] == u) 
						swap(U[e] , V[e]);
					edge.pb(e);
				}
			}
		}
		return;
	};

	int V1 = V[lovelyEdge];
	int V2 = U[lovelyEdge];

	bfs(V1 , d1 , edge1);
	bfs(V2 , d2 , edge2);


	fill(all(active) , false);
	rep(i , 0 , N) if (d1[i] < d2[i]) active[i] = true;
	bfs(V1 , d3 , edge1);



	fill(all(active) , false);
	rep(i , 0 , N) if (d2[i] < d1[i]) active[i] = true;
	bfs(V2 , d3 , edge2);


	// faze 4 : peyd akardan s O t:

	auto finder = [&](int root, vi&d ,  vi & edge) {
		ll len2 = -1;

		{
			vi local(M , 1);
			for (auto e : edge) local[e] = 0;
			len2 = ask(local);
		}

		int lo = -1, hi = edge.size() - 1;
		while (lo != hi - 1) {
			int mid = lo + hi >> 1;

			vi local(M , 1);
			rep(i , 0 , mid + 1)
				local[edge[i]] = 0;

			if (ask(local) == len2) hi = mid;
			else lo = mid;
		} 
		if (hi == 0) return root;
		return U[edge[hi]];
	};

	int S = finder(V1 , d1 , edge1);
	int T = finder(V2 , d2 ,edge2);

	if (true) 
		assert(d1[S] + 1 + d2[T] <= len);

	answer(S , T);

	return;


}

Compilation message

highway.cpp: In function 'void find_pair(int, vi, vi, int, int)':
highway.cpp:34:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    int mid = lo + hi >> 1;
              ~~~^~~~
highway.cpp: In lambda function:
highway.cpp:112:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    int mid = lo + hi >> 1;
              ~~~^~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 324 KB Output is correct
4 Correct 2 ms 380 KB Output is correct
5 Correct 2 ms 248 KB Output is correct
6 Correct 2 ms 324 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 380 KB Output is correct
10 Correct 2 ms 248 KB Output is correct
11 Correct 2 ms 328 KB Output is correct
12 Correct 2 ms 376 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 380 KB Output is correct
2 Correct 23 ms 1288 KB Output is correct
3 Correct 246 ms 9320 KB Output is correct
4 Correct 242 ms 9388 KB Output is correct
5 Correct 202 ms 9396 KB Output is correct
6 Correct 190 ms 9392 KB Output is correct
7 Correct 249 ms 9324 KB Output is correct
8 Correct 220 ms 9388 KB Output is correct
9 Correct 223 ms 9508 KB Output is correct
10 Correct 212 ms 9364 KB Output is correct
11 Correct 260 ms 9280 KB Output is correct
12 Correct 235 ms 9296 KB Output is correct
13 Correct 265 ms 9264 KB Output is correct
14 Correct 251 ms 9292 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 1344 KB Output is correct
2 Correct 67 ms 2376 KB Output is correct
3 Correct 61 ms 3340 KB Output is correct
4 Correct 165 ms 9276 KB Output is correct
5 Correct 169 ms 9288 KB Output is correct
6 Correct 174 ms 9288 KB Output is correct
7 Correct 151 ms 9336 KB Output is correct
8 Correct 159 ms 9268 KB Output is correct
9 Correct 140 ms 9332 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 296 KB Output is correct
2 Correct 22 ms 1276 KB Output is correct
3 Correct 164 ms 7504 KB Output is correct
4 Correct 250 ms 9392 KB Output is correct
5 Correct 229 ms 9380 KB Output is correct
6 Correct 210 ms 9380 KB Output is correct
7 Correct 199 ms 9376 KB Output is correct
8 Correct 215 ms 9376 KB Output is correct
9 Correct 190 ms 9324 KB Output is correct
10 Correct 217 ms 9388 KB Output is correct
11 Correct 226 ms 9284 KB Output is correct
12 Correct 272 ms 9288 KB Output is correct
13 Correct 255 ms 9304 KB Output is correct
14 Correct 232 ms 9284 KB Output is correct
15 Correct 215 ms 9316 KB Output is correct
16 Correct 227 ms 9324 KB Output is correct
17 Correct 239 ms 9240 KB Output is correct
18 Correct 244 ms 9288 KB Output is correct
19 Correct 206 ms 9328 KB Output is correct
20 Correct 298 ms 9300 KB Output is correct
21 Correct 193 ms 9648 KB Output is correct
22 Correct 164 ms 9672 KB Output is correct
23 Correct 177 ms 9604 KB Output is correct
24 Correct 201 ms 9620 KB Output is correct
25 Correct 222 ms 9348 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Runtime error 17 ms 2536 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# Verdict Execution time Memory Grader output
1 Runtime error 28 ms 2604 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -