#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, ptr1, ptr2, ptr3, ptrq1, ptrq2, ptre, X[100005], Y[100005], A[200005], B[200005], dist[400005], standing[400005], Q[400005];
ii leftmost[200005], upmost[200005], edges[400005];
bitset<400005> vis, up, down, lft, rig;
vector<int> adj2[400005];
int tl(int x) {
return (x - 1) * 4 + 1;
}
int tr(int x) {
return (x - 1) * 4 + 2;
}
int bl(int x) {
return (x - 1) * 4 + 3;
}
int br(int x) {
return (x - 1) * 4 + 4;
}
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) {
if (x == lnk[x]) return x;
return lnk[x] = find(lnk[x]);
}
void unite(int a, int b) {
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() {
vis.reset();
up.reset();
down.reset();
lft.reset();
rig.reset();
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];
if (X[A[i]] == X[B[i]]) {
leftmost[ptr1++] = mp(X[A[i]], A[i]);
} else {
upmost[ptr2++] = mp(Y[A[i]], A[i]);
}
}
sort(leftmost, leftmost + ptr1, greater<ii>());
sort(upmost, upmost + ptr2);
for (int i = 1; i <= W; i++) {
if (X[A[i]] == X[B[i]] && Y[A[i]] > Y[B[i]]) {
// down
down[A[i]] = 1;
up[B[i]] = 1;
ufds::unite(bl(A[i]), tl(B[i]));
ufds::unite(br(A[i]), tr(B[i]));
} else if (X[A[i]] == X[B[i]] && Y[A[i]] < Y[B[i]]) {
// up
up[A[i]] = 1;
down[B[i]] = 1;
ufds::unite(tl(A[i]), bl(B[i]));
ufds::unite(tr(A[i]), br(B[i]));
} else if (Y[A[i]] == Y[B[i]] && X[A[i]] > X[B[i]]) {
// left
lft[A[i]] = 1;
rig[B[i]] = 1;
ufds::unite(bl(A[i]), br(B[i]));
ufds::unite(tl(A[i]), tr(B[i]));
} else if (Y[A[i]] == Y[B[i]] && X[A[i]] < X[B[i]]) {
// right
rig[A[i]] = 1;
lft[B[i]] = 1;
ufds::unite(br(A[i]), bl(B[i]));
ufds::unite(tr(A[i]), tl(B[i]));
} else {
assert(0);
}
}
for (int i = 1; i <= N; i++) {
if (!down[i]) {
ufds::unite(bl(i), br(i));
}
if (!up[i]) {
ufds::unite(tl(i), tr(i));
}
if (!lft[i]) {
ufds::unite(tl(i), bl(i));
}
if (!rig[i]) {
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));
if (down[i]) {
if (ubl != ubr) {
edges[ptre++] = mp(min(ubl, ubr), max(ubl, ubr));
}
}
if (up[i]) {
if (utl != utr) {
edges[ptre++] = mp(min(utl, utr), max(utl, utr));
}
}
if (lft[i]) {
if (utl != ubl) {
edges[ptre++] = mp(min(utl, ubl), max(utl, ubl));
}
}
if (rig[i]) {
if (utr != ubr) {
edges[ptre++] = mp(min(utr, ubr), max(utr, ubr));
}
}
}
sort(edges, edges + ptre);
ptre = unique(edges, edges + ptre) - edges;
for (int i = 0; i < ptre; i++) {
auto [u, v] = edges[i];
adj2[u].pb(v);
adj2[v].pb(u);
}
while (ptr1 || ptr2) {
if (ptr1) {
source = ufds::find(tl(leftmost[ptr1 - 1].second));
} else {
source = ufds::find(tl(upmost[ptr2 - 1].second));
}
ptrq1 = ptrq2 = 0;
Q[ptrq2++] = source;
vis[source] = 1;
while (ptrq1 < ptrq2) {
int u = Q[ptrq1++];
for (auto v : adj2[u]) {
if (!vis[v]) {
vis[v] = 1;
dist[v] = dist[u] + 1;
Q[ptrq2++] = v;
}
}
}
while (ptr1) {
if (vis[ufds::find(tl(leftmost[ptr1 - 1].second))]) ptr1--;
else break;
}
while (ptr2) {
if (vis[ufds::find(tl(upmost[ptr2 - 1].second))]) ptr2--;
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[ptr3++] = 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[ptr3++] = 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[ptr3++] = 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[ptr3++] = i;
} else {
assert(0);
}
}
cout << ptr3 << '\n';
for (int i = 0; i < ptr3; i++) {
cout << standing[i] << '\n';
}
}
Compilation message
flood.cpp:73:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
73 | main() {
| ^~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
9940 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
10044 KB |
Output is correct |
2 |
Correct |
5 ms |
9932 KB |
Output is correct |
3 |
Correct |
5 ms |
9920 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
9940 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
9940 KB |
Output is correct |
2 |
Correct |
5 ms |
10068 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
9940 KB |
Output is correct |
2 |
Correct |
4 ms |
10048 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
9940 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
10008 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
10068 KB |
Output is correct |
2 |
Correct |
5 ms |
10068 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
10068 KB |
Output is correct |
2 |
Correct |
5 ms |
10068 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
16 ms |
11988 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
38 ms |
16504 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
44 ms |
19160 KB |
Output is correct |
2 |
Correct |
115 ms |
25328 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
92 ms |
20716 KB |
Output is correct |
2 |
Correct |
128 ms |
26604 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
107 ms |
25148 KB |
Output is correct |
2 |
Correct |
59 ms |
18792 KB |
Output is correct |