#include <bits/stdc++.h>
#include "gardenlib.h"
using namespace std;
int _left(int x) {
return x<<1;
}
int _right(int x) {
return x<<1|1;
}
bool is_left(int x) {
return _left(x/2) == x;
}
vector<int> make_functional_graph(int n, int E[][2], int m) {
vector<int> F(2 * n);
vector<vector<int>> best(n);
for (int i = 0; i < m; ++i) {
int u = E[i][0], v = E[i][1];
best[u].emplace_back(v);
best[v].emplace_back(u);
}
for (int i = 0; i < n; ++i) {
if (best[i].size() == 1) {
best[i].emplace_back(best[i][0]);
}
}
for (int i = 0; i < n; ++i) {
int a = best[i][0], b = best[i][1];
F[_left(i)] = best[a][0] == i ? _right(a) : _left(a);
F[_right(i)] = best[b][0] == i ? _right(b) : _left(b);
}
return F;
}
vector<vector<int>> make_reverse_functional(vector<int> F) {
vector<vector<int>> Gt(F.size());
for (int i = 0; i < F.size(); ++i) {
Gt[F[i]].emplace_back(i);
}
return Gt;
}
const int inf = 1e9;
vector<int> bfs(vector<vector<int>> G, int src) {
vector<int> dis(G.size(), inf);
dis[src] = 0;
queue<int> Q;
Q.push(src);
while (not Q.empty()) {
int q = Q.front(); Q.pop();
for (int v : G[q]) {
if (dis[q] + 1 < dis[v]) {
dis[v] = dis[q] + 1;
Q.push(v);
}
}
}
return dis;
}
vector<int> get_cycle_from_functional(vector<int> F, int x) {
vector<int> cycle;
vector<bool> vis(F.size());
while (not vis[x]) {
vis[x] = 1;
x = F[x];
}
int t = x;
do {
cycle.emplace_back(x);
x = F[x];
} while (x != t);
return cycle;
}
bool is_in(int t, vector<int> v) {
for (int e : v) {
if (e == t) {
return 1;
}
}
return 0;
}
vector<int> solve(vector<int> F, int x) {
auto dis = bfs(make_reverse_functional(F), x);
auto cycle = get_cycle_from_functional(F, x);
int cycle_len = cycle.size();
int n = F.size();
vector<int> ans(n);
if (is_in(x, cycle)) {
for (int i = 0; i < n; ++i) {
if (dis[i] >= inf) continue;
if (not is_left(i) and F[_left(i)] / 2 != F[_right(i)] / 2) continue;
ans[dis[i]] += 1;
}
for (int i = 0; i + cycle_len < n; ++i) {
ans[i + cycle_len] += ans[i];
}
} else {
for (int i = 0; i < n; ++i) {
if (dis[i] >= inf) continue;
if (not is_left(i)) continue;
ans[dis[i]] += 1;
}
}
return ans;
}
void count_routes(int n, int m, int p, int R[][2], int q, int Q[]) {
auto G = make_functional_graph(n, R, m);
auto ans1 = solve(G, _left(p));
auto ans2 = solve(G, _right(p));
bool o1 = is_in(_left(p), get_cycle_from_functional(G, _left(p)));
bool o2 = is_in(_right(p), get_cycle_from_functional(G, _right(p)));
for (int i = 0; i < q; ++i) {
int temp = o1 ? ans1[Q[i] % (2 * n)] : (Q[i] >= 2*n ? 0 : ans1[Q[i]]);
if (G[_left(p)] / 2 != G[_right(p)] / 2) {
temp += o2 ? ans2[Q[i] % (2 * n)] : (Q[i] >= 2*n ? 0 : ans2[Q[i]]);
}
answer(temp);
}
}
Compilation message
garden.cpp: In function 'std::vector<std::vector<int> > make_reverse_functional(std::vector<int>)':
garden.cpp:40:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < F.size(); ++i) {
~~^~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
504 KB |
Output is correct |
| 2 |
Correct |
5 ms |
504 KB |
Output is correct |
| 3 |
Correct |
6 ms |
504 KB |
Output is correct |
| 4 |
Incorrect |
5 ms |
376 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
504 KB |
Output is correct |
| 2 |
Correct |
5 ms |
504 KB |
Output is correct |
| 3 |
Correct |
6 ms |
504 KB |
Output is correct |
| 4 |
Incorrect |
5 ms |
376 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
504 KB |
Output is correct |
| 2 |
Correct |
5 ms |
504 KB |
Output is correct |
| 3 |
Correct |
6 ms |
504 KB |
Output is correct |
| 4 |
Incorrect |
5 ms |
376 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
