oj.uz

Submission #108106

# Submission time Handle Problem Language Result Execution time Memory
108106 2019-04-27T10:44:57 Z Noam527 Highway Tolls (IOI18_highway) C++17
100 / 100
 354 ms 12208 KB 
#include <bits/stdc++.h>
#define CHECK cout << "ok" << endl
#define finish(x) return cout << x << endl, 0
typedef long long ll;
typedef long double ldb;
const int md = 1e9 + 7;
const ll inf = 1e18;
const int OO = 0;
const int OOO = 1;
using namespace std;

void answer(int s, int t);

ll ask(const vector<int> &w);

struct edge {
	int to, i;
	edge() {}
	edge(int tt, int ii) {
		to = tt;
		i = ii;
	}
};

vector<int> w;
vector<int> ord;
vector<int> special;

int n, m;
ll d;
vector<vector<edge>> g;
vector<int> vis, dep;

int crit;

ll f(int x) {
	for (int i = 0; i < x; i++) w[ord[i]] = 0;
	for (int i = x; i < ord.size(); i++) w[ord[i]] = 1;
	return ask(w);
}

void bfs(int v) {
	ord.clear();
	vis.resize(n, 0);
	dep.resize(n, 0);
	vis[v] = 1;
	queue<int> q;
	q.push(v);
	while (!q.empty()) {
		int x = q.front();
		q.pop();
		for (const auto &i : g[x])
			if (!vis[i.to]) {
				dep[i.to] = dep[x] + 1;
				ord.push_back(i.i);
				vis[i.to] = 1;
				q.push(i.to);
			}
	}
}
void dfs(int v) {
	vis[v] = 1;
	for (const auto &i : g[v])
		if (!vis[i.to] && w[i.i] == 0) {
			special[i.i] = 1;
			dfs(i.to);
		}
}

void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
	if (N == 2) {
		answer(0, 1);
		return;
	}
	n = N;
	g.resize(n);
	m = U.size();
	w.resize(m);
	for (int i = 0; i < m; i++) {
		g[U[i]].push_back(edge(V[i], i));
		g[V[i]].push_back(edge(U[i], i));
	}
	for (auto &i : w) i = 0;
	d = ask(w);
	if (OO) cout << "d = " << d << '\n';
	int lo, hi, mid;

	// 1: find edge on shortest path
	ord.resize(m);
	for (int i = 0; i < m; i++) ord[i] = i;
	lo = 0, hi = m - 1;
	while (lo < hi) {
		mid = (lo + hi + 1) / 2;
		if (f(mid) == d) hi = mid - 1;
		else lo = mid;
	}
	crit = lo;
	if (OO) cout << "critical edge index " << crit << ", (" << U[crit] << ", " << V[crit] << ")\n";
	// 2: root at 1 end of the edge, and bsearch in the subtree of the other for S/T
	for (auto &i : w) i = 1;
	// prioritize the critical edge
	for (auto &i : g[U[crit]])
		if (i.i == crit) {
			swap(i, g[U[crit]][0]);
		}
	bfs(U[crit]);
	for (auto &i : ord) w[i] = 0;

	// determine all edges in the subtree of the other end
	for (auto &i : vis) i = 0;
	vis[U[crit]] = 1;
	special.resize(m, 0);
	special[crit] = 1;
	dfs(V[crit]);
	vector<int> ord1, ord2;
	for (const auto &i : ord)
		if (special[i])
			ord1.push_back(i);
		else
			ord2.push_back(i);

	if (OO) {
		cout << "rooted at " << U[crit] << '\n';
		cout << "bfs: ";
		for (const auto &i : ord) cout << i << " "; cout << '\n';
		cout << "ord1: ";
		for (const auto &i : ord1) cout << i << " "; cout << '\n';
		cout << "ord2: ";
		for (const auto &i : ord2) cout << i << " "; cout << '\n';
		cout << "dep: ";
		for (const auto &i : dep) cout << i << " "; cout << '\n';
	}

	// bsearch in the subtree
	ord = ord1;
	lo = 0, hi = (int)ord.size() - 1;
	while (lo < hi) {
		mid = (lo + hi + 1) / 2;
		if (f(mid) == d) hi = mid - 1;
		else lo = mid;
	}
	int S, T;
	if (OO) {
		cout << "first bsearch yields edge " << ord[lo] << '\n';
	}
	if (dep[U[ord[lo]]] > dep[V[ord[lo]]]) S = U[ord[lo]];
	else S = V[ord[lo]];
	if (OO) cout << "resulting in S = " << S << '\n';

	if ((ll)A * dep[S] == d) {
		T = U[crit];
		answer(S, T);
		return;
	}

	// bsearch on everything else
	for (auto &i : ord1) w[i] = 0;
	ord = ord2;
	lo = 0, hi = (int)ord.size() - 1;
	while (lo < hi) {
		mid = (lo + hi + 1) / 2;
		if (f(mid) == d) hi = mid - 1;
		else lo = mid;
	}
	if (OO) {
		cout << "second bsearch yields edge " << ord[lo] << '\n';
	}
	if (dep[U[ord[lo]]] > dep[V[ord[lo]]]) T = U[ord[lo]];
	else T = V[ord[lo]];
	if (OO) cout << "resulting in T = " << T << '\n';

	answer(S, T);
}

Compilation message

highway.cpp: In function 'll f(int)':
highway.cpp:38:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = x; i < ord.size(); i++) w[ord[i]] = 1;
                  ~~^~~~~~~~~~~~
highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:125:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for (const auto &i : ord) cout << i << " "; cout << '\n';
   ^~~
highway.cpp:125:47: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   for (const auto &i : ord) cout << i << " "; cout << '\n';
                                               ^~~~
highway.cpp:127:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for (const auto &i : ord1) cout << i << " "; cout << '\n';
   ^~~
highway.cpp:127:48: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   for (const auto &i : ord1) cout << i << " "; cout << '\n';
                                                ^~~~
highway.cpp:129:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for (const auto &i : ord2) cout << i << " "; cout << '\n';
   ^~~
highway.cpp:129:48: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   for (const auto &i : ord2) cout << i << " "; cout << '\n';
                                                ^~~~
highway.cpp:131:3: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   for (const auto &i : dep) cout << i << " "; cout << '\n';
   ^~~
highway.cpp:131:47: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   for (const auto &i : dep) cout << i << " "; cout << '\n';
                                               ^~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 412 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 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 320 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 252 KB Output is correct
10 Correct 2 ms 328 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 4 ms 376 KB Output is correct
2 Correct 45 ms 1340 KB Output is correct
3 Correct 258 ms 9596 KB Output is correct
4 Correct 207 ms 9592 KB Output is correct
5 Correct 228 ms 9588 KB Output is correct
6 Correct 194 ms 9568 KB Output is correct
7 Correct 203 ms 9592 KB Output is correct
8 Correct 183 ms 9600 KB Output is correct
9 Correct 199 ms 9688 KB Output is correct
10 Correct 207 ms 9596 KB Output is correct
11 Correct 229 ms 9612 KB Output is correct
12 Correct 219 ms 10064 KB Output is correct
13 Correct 221 ms 9160 KB Output is correct
14 Correct 224 ms 9112 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 1528 KB Output is correct
2 Correct 39 ms 2676 KB Output is correct
3 Correct 61 ms 3404 KB Output is correct
4 Correct 168 ms 10232 KB Output is correct
5 Correct 132 ms 10792 KB Output is correct
6 Correct 177 ms 9548 KB Output is correct
7 Correct 175 ms 9256 KB Output is correct
8 Correct 167 ms 9892 KB Output is correct
9 Correct 175 ms 9724 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 45 ms 1372 KB Output is correct
3 Correct 161 ms 7660 KB Output is correct
4 Correct 193 ms 9736 KB Output is correct
5 Correct 167 ms 9592 KB Output is correct
6 Correct 175 ms 9584 KB Output is correct
7 Correct 201 ms 9600 KB Output is correct
8 Correct 204 ms 9588 KB Output is correct
9 Correct 218 ms 9468 KB Output is correct
10 Correct 198 ms 9592 KB Output is correct
11 Correct 220 ms 9632 KB Output is correct
12 Correct 193 ms 9344 KB Output is correct
13 Correct 213 ms 9444 KB Output is correct
14 Correct 222 ms 9828 KB Output is correct
15 Correct 194 ms 9588 KB Output is correct
16 Correct 207 ms 9604 KB Output is correct
17 Correct 260 ms 9852 KB Output is correct
18 Correct 201 ms 9876 KB Output is correct
19 Correct 213 ms 9588 KB Output is correct
20 Correct 203 ms 10192 KB Output is correct
21 Correct 185 ms 10040 KB Output is correct
22 Correct 164 ms 10124 KB Output is correct
23 Correct 169 ms 9776 KB Output is correct
24 Correct 182 ms 9840 KB Output is correct
25 Correct 204 ms 9256 KB Output is correct

Subtask #5
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 1444 KB Output is correct
2 Correct 29 ms 1400 KB Output is correct
3 Correct 231 ms 9992 KB Output is correct
4 Correct 232 ms 10588 KB Output is correct
5 Correct 304 ms 11516 KB Output is correct
6 Correct 311 ms 11552 KB Output is correct
7 Correct 306 ms 11712 KB Output is correct
8 Correct 290 ms 11628 KB Output is correct
9 Correct 228 ms 8008 KB Output is correct
10 Correct 246 ms 8332 KB Output is correct
11 Correct 262 ms 9056 KB Output is correct
12 Correct 303 ms 10676 KB Output is correct
13 Correct 268 ms 11204 KB Output is correct
14 Correct 319 ms 11520 KB Output is correct
15 Correct 314 ms 11668 KB Output is correct
16 Correct 269 ms 9236 KB Output is correct
17 Correct 193 ms 9884 KB Output is correct
18 Correct 209 ms 10068 KB Output is correct
19 Correct 180 ms 9952 KB Output is correct
20 Correct 203 ms 9980 KB Output is correct
21 Correct 310 ms 11996 KB Output is correct

Subtask #6
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 1380 KB Output is correct
2 Correct 21 ms 1352 KB Output is correct
3 Correct 254 ms 10024 KB Output is correct
4 Correct 286 ms 10268 KB Output is correct
5 Correct 250 ms 10576 KB Output is correct
6 Correct 299 ms 11628 KB Output is correct
7 Correct 248 ms 10148 KB Output is correct
8 Correct 289 ms 10296 KB Output is correct
9 Correct 354 ms 10580 KB Output is correct
10 Correct 292 ms 11596 KB Output is correct
11 Correct 321 ms 11488 KB Output is correct
12 Correct 310 ms 11580 KB Output is correct
13 Correct 253 ms 9204 KB Output is correct
14 Correct 240 ms 8328 KB Output is correct
15 Correct 259 ms 9088 KB Output is correct
16 Correct 240 ms 8336 KB Output is correct
17 Correct 273 ms 9088 KB Output is correct
18 Correct 230 ms 8404 KB Output is correct
19 Correct 277 ms 10700 KB Output is correct
20 Correct 280 ms 11156 KB Output is correct
21 Correct 313 ms 11744 KB Output is correct
22 Correct 311 ms 11596 KB Output is correct
23 Correct 319 ms 11688 KB Output is correct
24 Correct 302 ms 11604 KB Output is correct
25 Correct 309 ms 11608 KB Output is correct
26 Correct 294 ms 11728 KB Output is correct
27 Correct 211 ms 9904 KB Output is correct
28 Correct 189 ms 10036 KB Output is correct
29 Correct 204 ms 10236 KB Output is correct
30 Correct 204 ms 10036 KB Output is correct
31 Correct 194 ms 10008 KB Output is correct
32 Correct 191 ms 9888 KB Output is correct
33 Correct 218 ms 10168 KB Output is correct
34 Correct 189 ms 9896 KB Output is correct
35 Correct 177 ms 9944 KB Output is correct
36 Correct 206 ms 9840 KB Output is correct
37 Correct 203 ms 10160 KB Output is correct
38 Correct 228 ms 10076 KB Output is correct
39 Correct 313 ms 12208 KB Output is correct
40 Correct 316 ms 12208 KB Output is correct
41 Correct 277 ms 11992 KB Output is correct
42 Correct 296 ms 11764 KB Output is correct