oj.uz

Submission #139116

# Submission time Handle Problem Language Result Execution time Memory
139116 2019-07-31T09:38:14 Z MAMBA Highway Tolls (IOI18_highway) C++17
51 / 100
 260 ms 9420 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);
	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 , d1 , edge1);

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

			ll junk = ask(local);
			assert(junk >= len2);
			if (junk == 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 (false && A == 1 && B == 2) 
		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:110:17: 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 376 KB Output is correct
2 Correct 2 ms 404 KB Output is correct
3 Correct 3 ms 376 KB Output is correct
4 Correct 2 ms 324 KB Output is correct
5 Correct 2 ms 252 KB Output is correct
6 Correct 2 ms 408 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 328 KB Output is correct
9 Correct 2 ms 328 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 2 ms 248 KB Output is correct
12 Correct 2 ms 248 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 484 KB Output is correct
2 Correct 21 ms 1264 KB Output is correct
3 Correct 223 ms 9000 KB Output is correct
4 Correct 255 ms 8972 KB Output is correct
5 Correct 238 ms 9004 KB Output is correct
6 Correct 226 ms 8984 KB Output is correct
7 Correct 239 ms 9012 KB Output is correct
8 Correct 228 ms 9004 KB Output is correct
9 Correct 220 ms 8976 KB Output is correct
10 Correct 239 ms 8996 KB Output is correct
11 Correct 254 ms 8892 KB Output is correct
12 Correct 232 ms 8900 KB Output is correct
13 Correct 234 ms 8908 KB Output is correct
14 Correct 241 ms 8896 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 1308 KB Output is correct
2 Correct 41 ms 2284 KB Output is correct
3 Correct 49 ms 3232 KB Output is correct
4 Correct 169 ms 8888 KB Output is correct
5 Correct 190 ms 8932 KB Output is correct
6 Correct 162 ms 8952 KB Output is correct
7 Correct 172 ms 8972 KB Output is correct
8 Correct 168 ms 8896 KB Output is correct
9 Correct 178 ms 8984 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB Output is correct
2 Correct 19 ms 1384 KB Output is correct
3 Correct 174 ms 7112 KB Output is correct
4 Correct 215 ms 8996 KB Output is correct
5 Correct 199 ms 8992 KB Output is correct
6 Correct 229 ms 9028 KB Output is correct
7 Correct 219 ms 8992 KB Output is correct
8 Correct 200 ms 9008 KB Output is correct
9 Correct 227 ms 9000 KB Output is correct
10 Correct 209 ms 9000 KB Output is correct
11 Correct 260 ms 8904 KB Output is correct
12 Correct 253 ms 8904 KB Output is correct
13 Correct 254 ms 8908 KB Output is correct
14 Correct 256 ms 8916 KB Output is correct
15 Correct 227 ms 8960 KB Output is correct
16 Correct 224 ms 8996 KB Output is correct
17 Correct 251 ms 8888 KB Output is correct
18 Correct 256 ms 8912 KB Output is correct
19 Correct 213 ms 8940 KB Output is correct
20 Correct 225 ms 8892 KB Output is correct
21 Correct 161 ms 9252 KB Output is correct
22 Correct 195 ms 9420 KB Output is correct
23 Correct 204 ms 9256 KB Output is correct
24 Correct 211 ms 9228 KB Output is correct
25 Correct 249 ms 8964 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Incorrect 20 ms 1292 KB Output is incorrect: {s, t} is wrong.
2 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# Verdict Execution time Memory Grader output
1 Incorrect 28 ms 1336 KB Output is incorrect: {s, t} is wrong.
2 Halted 0 ms 0 KB -