#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
//~ #define int long long
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define ppb pop_back
#define eb emplace_back
#define g0(a) get<0>(a)
#define g1(a) get<1>(a)
#define g2(a) get<2>(a)
#define g3(a) get<3>(a)
#define g4(a) get<4>(a)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
using db = double;
using ll = long long;
using ld = long double;
using ii = pair<int, int>;
using iii = tuple<int, int, int>;
using iiii = tuple<int, int, int, int>;
using iiiii = tuple<int, int, int, int, int>;
template<class key, class value = null_type, class cmp = less<key> >
using ordered_set = tree<key, value, cmp, rb_tree_tag, tree_order_statistics_node_update>;
int N, W, source, X[100005], Y[100005], A[200005], B[200005], dist[400005];
bool vis[400005];
vector<int> standing;
map<ii, int> seen;
vector<int> adj[400005], adj2[400005];
queue<int> Q;
set<ii> leftmost, upmost, edges;
int conv(int r, int c) {
if (seen.find(mp(r, c)) != seen.end()) return seen[mp(r, c)];
assert((int)seen.size() + 1 <= 4 * N);
return seen[mp(r, c)] = seen.size() + 1;
}
int tl(int x) {
return conv(X[x] - 1, Y[x]);
}
int tr(int x) {
return conv(X[x], Y[x]);
}
int bl(int x) {
return conv(X[x] - 1, Y[x] - 1);
}
int br(int x) {
return conv(X[x], Y[x] - 1);
}
namespace ufds {
int n, lnk[400005], sz[400005];
void init(int n) {
ufds::n = n;
for (int i = 1; i <= n; i++) {
lnk[i] = i;
sz[i] = 1;
}
}
int find(int x) {
assert(1 <= x && x <= n);
if (x == lnk[x]) return x;
return lnk[x] = find(lnk[x]);
}
void unite(int a, int b) {
assert(1 <= a && a <= n && 1 <= b && b <= n);
a = find(a);
b = find(b);
if (a == b) return;
if (sz[b] > sz[a]) swap(a, b);
sz[a] += sz[b];
lnk[b] = a;
}
};
main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> N;
for (int i = 1; i <= N; i++) {
cin >> X[i] >> Y[i];
}
ufds::init(4 * N);
cin >> W;
for (int i = 1; i <= W; i++) {
cin >> A[i] >> B[i];
adj[A[i]].pb(B[i]);
adj[B[i]].pb(A[i]);
if (X[A[i]] == X[B[i]]) {
leftmost.emplace(X[A[i]], A[i]);
} else {
upmost.emplace(Y[A[i]], A[i]);
}
}
for (int i = 1; i <= N; i++) {
bool down = 0, up = 0, left = 0, right = 0;
for (int j : adj[i]) {
if (X[i] == X[j] && Y[i] > Y[j]) {
// i --> j goes down
down = 1;
ufds::unite(bl(i), tl(j));
} else if (X[i] == X[j] && Y[i] < Y[j]) {
// i --> j goes up
up = 1;
ufds::unite(tr(i), br(j));
} else if (Y[i] == Y[j] && X[i] > X[j]) {
// i --> j goes left
left = 1;
ufds::unite(tl(i), tr(j));
} else if (Y[i] == Y[j] && X[i] < X[j]) {
// i --> j goes right
right = 1;
ufds::unite(br(i), bl(j));
} else {
assert(0);
}
}
if (!down) {
ufds::unite(bl(i), br(i));
}
if (!up) {
ufds::unite(tl(i), tr(i));
}
if (!left) {
ufds::unite(tl(i), bl(i));
}
if (!right) {
ufds::unite(tr(i), br(i));
}
}
for (int i = 1; i <= N; i++) {
int utl = ufds::find(tl(i));
int utr = ufds::find(tr(i));
int ubl = ufds::find(bl(i));
int ubr = ufds::find(br(i));
for (int j : adj[i]) {
if (X[i] == X[j] && Y[i] > Y[j]) {
// i --> j goes down
if (ubl != ubr) {
edges.emplace(min(ubl, ubr), max(ubl, ubr));
}
} else if (X[i] == X[j] && Y[i] < Y[j]) {
// i --> j goes up
if (utl != utr) {
edges.emplace(min(utl, utr), max(utl, utr));
}
} else if (Y[i] == Y[j] && X[i] > X[j]) {
// i --> j goes left
if (ubl != utl) {
edges.emplace(min(ubl, utl), max(ubl, utl));
}
} else if (Y[i] == Y[j] && X[i] < X[j]) {
// i --> j goes right
if (utr != ubr) {
edges.emplace(min(utr, ubr), max(utr, ubr));
}
} else {
assert(0);
}
}
}
for (auto [u, v] : edges) {
adj2[u].pb(v);
adj2[v].pb(u);
}
while (!leftmost.empty() || !upmost.empty()) {
if (!leftmost.empty()) {
source = ufds::find(tl(leftmost.begin()->second));
} else {
source = ufds::find(tl(upmost.rbegin()->second));
}
//~ cout << "SOURCE " << source << '\n';
Q.push(source);
vis[source] = 1;
while (!Q.empty()) {
int u = Q.front();
Q.pop();
for (auto v : adj2[u]) {
if (!vis[v]) {
//~ cout << "VIS " << v << '\n';
vis[v] = 1;
dist[v] = dist[u] + 1;
Q.push(v);
}
}
}
while (!leftmost.empty()) {
if (vis[ufds::find(tl(leftmost.begin()->second))]) leftmost.erase(leftmost.begin());
else break;
}
while (!upmost.empty()) {
if (vis[ufds::find(tl(upmost.rbegin()->second))]) upmost.erase(--upmost.end());
else break;
}
}
for (int i = 1; i <= W; i++) {
if (X[A[i]] == X[B[i]] && Y[A[i]] > Y[B[i]]) {
// down
if (dist[ufds::find(bl(A[i]))] == dist[ufds::find(br(A[i]))]) standing.pb(i);
} else if (X[A[i]] == X[B[i]] && Y[A[i]] < Y[B[i]]) {
// up
if (dist[ufds::find(tl(A[i]))] == dist[ufds::find(tr(A[i]))]) standing.pb(i);
} else if (Y[A[i]] == Y[B[i]] && X[A[i]] > X[B[i]]) {
// left
if (dist[ufds::find(bl(A[i]))] == dist[ufds::find(tl(A[i]))]) standing.pb(i);
} else if (Y[A[i]] == Y[B[i]] && X[A[i]] < X[B[i]]) {
// right
if (dist[ufds::find(br(A[i]))] == dist[ufds::find(tr(A[i]))]) standing.pb(i);
} else {
assert(0);
}
}
cout << standing.size() << '\n';
for (auto i : standing) {
//~ cout << i << ": " << A[i] << ' ' << B[i] << '\n';
cout << i << '\n';
}
}
Compilation message
flood.cpp:84:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
84 | main() {
| ^~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
19156 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
9 ms |
19156 KB |
Output is correct |
2 |
Correct |
9 ms |
19156 KB |
Output is correct |
3 |
Correct |
10 ms |
19132 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
19136 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
9 ms |
19120 KB |
Output is correct |
2 |
Correct |
11 ms |
19392 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
19156 KB |
Output is correct |
2 |
Correct |
10 ms |
19128 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
12 ms |
19156 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
11 ms |
19260 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
19284 KB |
Output is correct |
2 |
Correct |
11 ms |
19400 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
11 ms |
19328 KB |
Output is correct |
2 |
Correct |
13 ms |
19336 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
99 ms |
29200 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
336 ms |
48316 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
324 ms |
59488 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
928 ms |
65536 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
798 ms |
65536 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |