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Submission #139132

# Submission time Handle Problem Language Result Execution time Memory
139132 2019-07-31T09:54:52 Z MAMBA Highway Tolls (IOI18_highway) C++17
51 / 100
 321 ms 9764 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);
		}

		auto check = [&](int mid) {
			vi local(M , 1);
			rep(i , 0 , mid + 1)
				local[edge[i]] = 0;

			return ask(local) == len2;
		};

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


			if (check(mid)) hi = mid;
			else lo = mid;
		}
		if(hi && check(hi - 1)) while(true);
		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:119:17: 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 248 KB Output is correct
3 Correct 2 ms 324 KB Output is correct
4 Correct 2 ms 452 KB Output is correct
5 Correct 2 ms 248 KB Output is correct
6 Correct 2 ms 248 KB Output is correct
7 Correct 2 ms 252 KB Output is correct
8 Correct 2 ms 248 KB Output is correct
9 Correct 2 ms 376 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 412 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 35 ms 1268 KB Output is correct
3 Correct 235 ms 9384 KB Output is correct
4 Correct 264 ms 9388 KB Output is correct
5 Correct 321 ms 9292 KB Output is correct
6 Correct 255 ms 9388 KB Output is correct
7 Correct 284 ms 9384 KB Output is correct
8 Correct 223 ms 9388 KB Output is correct
9 Correct 225 ms 9384 KB Output is correct
10 Correct 253 ms 9376 KB Output is correct
11 Correct 262 ms 9288 KB Output is correct
12 Correct 229 ms 9228 KB Output is correct
13 Correct 173 ms 9216 KB Output is correct
14 Correct 237 ms 9292 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 1360 KB Output is correct
2 Correct 65 ms 2372 KB Output is correct
3 Correct 49 ms 3352 KB Output is correct
4 Correct 174 ms 9284 KB Output is correct
5 Correct 166 ms 9268 KB Output is correct
6 Correct 200 ms 9280 KB Output is correct
7 Correct 181 ms 9344 KB Output is correct
8 Correct 147 ms 9280 KB Output is correct
9 Correct 178 ms 9360 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 396 KB Output is correct
2 Correct 14 ms 1360 KB Output is correct
3 Correct 159 ms 7428 KB Output is correct
4 Correct 226 ms 9380 KB Output is correct
5 Correct 215 ms 9352 KB Output is correct
6 Correct 220 ms 9424 KB Output is correct
7 Correct 237 ms 9388 KB Output is correct
8 Correct 225 ms 9372 KB Output is correct
9 Correct 242 ms 9396 KB Output is correct
10 Correct 266 ms 9404 KB Output is correct
11 Correct 269 ms 9296 KB Output is correct
12 Correct 246 ms 9312 KB Output is correct
13 Correct 223 ms 9296 KB Output is correct
14 Correct 250 ms 9316 KB Output is correct
15 Correct 221 ms 9340 KB Output is correct
16 Correct 213 ms 9416 KB Output is correct
17 Correct 246 ms 9292 KB Output is correct
18 Correct 252 ms 9212 KB Output is correct
19 Correct 222 ms 9404 KB Output is correct
20 Correct 232 ms 9300 KB Output is correct
21 Correct 157 ms 9596 KB Output is correct
22 Correct 208 ms 9676 KB Output is correct
23 Correct 192 ms 9764 KB Output is correct
24 Correct 203 ms 9616 KB Output is correct
25 Correct 258 ms 9320 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Runtime error 52 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 29 ms 2572 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -