| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 695053 |
2023-02-04T17:13:25 Z |
null_awe |
Joker (BOI20_joker) |
C++14 |
|
0 ms |
212 KB |
#include <iostream>
#include <vector>
#include <set>
#include <queue>
using namespace std;
#define pii pair<int, int>
struct link_cut_tree {
int n;
set<pii> edges;
vector<int> r, p;
link_cut_tree(int n) : n(n), r(n, 1), p(n) {
for (int i = 0; i < n; ++i) p[i] = i;
}
int find(int a) {
return a == p[a] ? a : p[a] = find(p[a]);
}
bool same(int a, int b) {
return find(a) == find(b);
}
int sz(int a) {
return r[find(a)];
}
void link(int a, int b) {
a = find(a), b = find(b);
if (a == b) return;
if (r[a] < r[b]) swap(a, b);
p[b] = a, r[a] += r[b];
}
void calc() {
for (int i = 0; i < n; ++i) r[i] = 1, p[i] = i;
for (pii edge : edges) link(edge.first, edge.second);
}
void add(int a, int b) {
// cout << "ADD " << a + 1 << ' ' << b + 1 << '\n';
edges.insert({a, b});
calc();
}
void erase(int a, int b) {
// cout << "ERASE " << a + 1 << ' ' << b + 1 << '\n';
edges.erase({a, b});
calc();
}
};
vector<bool> color;
vector<set<int>> adj;
vector<int> until;
int main() {
int n, m, q; cin >> n >> m >> q;
vector<pii> edges(m);
for (int i = 0; i < m; ++i) cin >> edges[i].first >> edges[i].second;
for (int i = 0; i < m; ++i) --edges[i].first, --edges[i].second;
color.resize(n), adj.resize(n), until.resize(m);
link_cut_tree lct(n);
int at = m - 1;
while (at >= 0) {
pii p = edges[at];
int a = p.first, b = p.second;
if (lct.same(a, b)) {
if (color[a] == color[b]) break;
--at;
adj[a].insert(b);
adj[b].insert(a);
lct.add(a, b);
continue;
} else {
int asz = lct.sz(a), bsz = lct.sz(b);
if (asz < bsz) swap(a, b);
color[b] = !color[a];
set<int> vis; vis.insert(b);
queue<int> q; q.push(b);
while (q.size()) {
int v = q.front(); q.pop();
for (int u : adj[v]) {
if (vis.count(u)) continue;
vis.insert(u);
color[u] = !color[v];
}
}
if (asz < bsz) swap(a, b);
--at;
adj[a].insert(b);
adj[b].insert(a);
lct.add(a, b);
}
// for (int c : color) cout << c << ' ';
// cout << '\n';
}
++at;
until[0] = at - 1;
for (int i = 1; i < m; ++i) {
while (at <= m) {
pii p = edges[i - 1];
int a = p.first, b = p.second;
// cout << i << ' ' << at << '\n';
if (lct.same(a, b) && color[a] == color[b] && at < m) {
p = edges[at];
a = p.first, b = p.second;
++at;
adj[a].erase(b);
adj[b].erase(a);
lct.erase(a, b);
} else {
adj[a].insert(b);
adj[b].insert(a);
if (!lct.same(a, b)) {
int asz = lct.sz(a), bsz = lct.sz(b);
if (asz < bsz) swap(a, b);
color[b] = !color[a];
set<int> vis; vis.insert(b);
queue<int> q; q.push(b);
while (q.size()) {
int v = q.front(); q.pop();
for (int u : adj[v]) {
if (vis.count(u)) continue;
vis.insert(u);
color[u] = !color[v];
}
}
if (asz < bsz) swap(a, b);
}
lct.add(a, b);
break;
}
// for (int c : color) cout << c << ' ';
// cout << '\n';
}
until[i] = at - 1;
}
// for (int num : until) cout << num + 1 << ' ';
// cout << '\n';
for (int i = 0; i < q; ++i) {
int a, b; cin >> a >> b; --a, --b;
cout << (until[a] <= b ? "YES\n" : "NO\n");
}
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
