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Submission #139127

# Submission time Handle Problem Language Result Execution time Memory
139127 2019-07-31T09:50:13 Z MAMBA Highway Tolls (IOI18_highway) C++17
51 / 100
 343 ms 9676 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 (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:111:17: 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 324 KB Output is correct
2 Correct 2 ms 328 KB Output is correct
3 Correct 2 ms 248 KB Output is correct
4 Correct 2 ms 324 KB Output is correct
5 Correct 2 ms 248 KB Output is correct
6 Correct 2 ms 408 KB Output is correct
7 Correct 2 ms 292 KB Output is correct
8 Correct 1 ms 328 KB Output is correct
9 Correct 2 ms 248 KB Output is correct
10 Correct 2 ms 248 KB Output is correct
11 Correct 2 ms 320 KB Output is correct
12 Correct 2 ms 408 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 396 KB Output is correct
2 Correct 21 ms 1260 KB Output is correct
3 Correct 233 ms 9380 KB Output is correct
4 Correct 234 ms 9396 KB Output is correct
5 Correct 257 ms 9388 KB Output is correct
6 Correct 223 ms 9380 KB Output is correct
7 Correct 248 ms 9400 KB Output is correct
8 Correct 255 ms 9388 KB Output is correct
9 Correct 228 ms 9392 KB Output is correct
10 Correct 216 ms 9392 KB Output is correct
11 Correct 239 ms 9300 KB Output is correct
12 Correct 230 ms 9304 KB Output is correct
13 Correct 236 ms 9200 KB Output is correct
14 Correct 216 ms 9276 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 1352 KB Output is correct
2 Correct 62 ms 2368 KB Output is correct
3 Correct 35 ms 3348 KB Output is correct
4 Correct 153 ms 9288 KB Output is correct
5 Correct 156 ms 9284 KB Output is correct
6 Correct 138 ms 9292 KB Output is correct
7 Correct 200 ms 9332 KB Output is correct
8 Correct 194 ms 9208 KB Output is correct
9 Correct 193 ms 9324 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 392 KB Output is correct
2 Correct 15 ms 1256 KB Output is correct
3 Correct 231 ms 7436 KB Output is correct
4 Correct 191 ms 9320 KB Output is correct
5 Correct 195 ms 9380 KB Output is correct
6 Correct 217 ms 9260 KB Output is correct
7 Correct 210 ms 9308 KB Output is correct
8 Correct 219 ms 9392 KB Output is correct
9 Correct 185 ms 9396 KB Output is correct
10 Correct 340 ms 9412 KB Output is correct
11 Correct 340 ms 9260 KB Output is correct
12 Correct 217 ms 9188 KB Output is correct
13 Correct 201 ms 9232 KB Output is correct
14 Correct 234 ms 9312 KB Output is correct
15 Correct 159 ms 9364 KB Output is correct
16 Correct 204 ms 9396 KB Output is correct
17 Correct 335 ms 9212 KB Output is correct
18 Correct 343 ms 9248 KB Output is correct
19 Correct 269 ms 9388 KB Output is correct
20 Correct 204 ms 9240 KB Output is correct
21 Correct 153 ms 9636 KB Output is correct
22 Correct 193 ms 9676 KB Output is correct
23 Correct 197 ms 9656 KB Output is correct
24 Correct 177 ms 9608 KB Output is correct
25 Correct 343 ms 9304 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Runtime error 21 ms 2528 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 35 ms 2592 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -