#include <bits/stdc++.h>
#ifdef local
#define debug(x...) qqbx(#x, x)
#define pary(x...) danb(#x, x)
#define safe std::cerr<<__PRETTY_FUNCTION__<<" line "<<__LINE__<<" safe\n"
template <typename ...T> void qqbx(const char *s, T ...a) {
int cnt = sizeof...(T);
((std::cerr << "(" << s << ") = ("), ..., (std::cerr << a << (--cnt ? ", " : ")\n")));
}
template <typename T> void danb(const char *t, T L, T R) {
std::cerr << "[ " << t << " ] = [ ";
for (int f = 0; L != R; ++L) std::cerr << (f++ ? ", " : "") << *L;
std::cerr << " ]\n";
}
#else
#define debug(...) ((void)0)
#define pary(...) ((void)0)
#define safe ((void)0)
#endif // local
using namespace std;
// #include "lib1270.h"
const int maxn = 5005, K = 4;
struct Dsu {
int pa[maxn], rk[maxn];
int deg[maxn];
bool ok;
Dsu() {
memset(pa, 0, sizeof pa);
memset(rk, 0, sizeof rk);
memset(deg, 0, sizeof deg);
}
void init(int n) {
for (int i = 0; i < n; i++) pa[i] = i, rk[i] = 0, deg[i] = 0;
ok = true;
}
int anc(int x) { return x==pa[x] ? x : pa[x]=anc(pa[x]); }
bool join(int x, int y) {
if (++deg[x] == 3) ok = false;
if (++deg[y] == 3) ok = false;
if ((x=anc(x)) == (y=anc(y))) return ok = false;
if (rk[x] < rk[y]) swap(x, y);
return pa[y] = x, rk[x]!=rk[y] || ++rk[x];
}
} dsu[K];
vector<int> cand;
pair<int,int> E[maxn];
vector<int> adj[maxn];
bool inCand[maxn];
int tot, N;
bool hasFour;
void Init(int _N) {
N = _N;
for (int i = 0; i < K; i++)
dsu[i].init(N);
for (int i = 0; i < N; i++)
adj[i].clear();
for (int i = 0; i < N; i++)
inCand[i] = false;
cand.clear();
tot = 0;
hasFour = false;
}
void addCand(int x) {
if (cand.size() >= K) return;
if (inCand[x]) return;
inCand[x] = true;
int pos = cand.size();
cand.push_back(x);
for (int i = 0; i < tot; i++)
if (x != E[i].first && x != E[i].second)
dsu[pos].join(E[i].first, E[i].second);
}
void Link(int a, int b) {
adj[a].push_back(b);
adj[b].push_back(a);
for (int x: {a, b}) {
if (!hasFour && adj[x].size() == 4) {
hasFour = true;
debug("NO", x);
pary(cand.begin(),cand.end());
if (inCand[x]) continue;
inCand[x] = true;
debug("FOUR", x);
if (cand.empty()) cand.push_back(7122);
cand[0] = x;
dsu[0].init(N);
for (int i = 0; i < tot; i++)
if (x != E[i].first && x != E[i].second)
dsu[0].join(E[i].first, E[i].second);
}
}
if (adj[a].size() == 3) {
addCand(a);
for (int j: adj[a])
addCand(j);
}
if (adj[b].size() == 3) {
addCand(b);
for (int j: adj[b])
addCand(j);
}
E[tot++] = { a, b };
for (int i = 0; i < cand.size(); i++)
if (a != cand[i] && b != cand[i]) {
dsu[i].join(a, b);
}
}
int CountCritical() {
if (cand.size() == 0) return N;
pary(cand.begin(),cand.end());
int ans = 0;
for (int i = 0; i < N; i++) {
dsu[0].init(N);
for (int j = 0; j < tot; j++) if (i != E[j].first && i != E[j].second) dsu[0].join(E[j].first, E[j].second);
if (dsu[0].ok) ++ans;
}
// for (int i = 0; i < cand.size(); i++) if (dsu[i].ok) ++ans;
return ans;
}
#ifdef local
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0);
int n;
cin >> n;
Init(n);
int q;
cin >> q;
while (q--) {
char c;
cin >> c;
if (c == 'L') {
int x, y;
cin >> x >> y;
Link(x, y);
} else if (c == 'Q') {
cout << CountCritical() << '\n';
}
}
}
#endif // local
/*
4
6
L 1 2
L 2 3
L 4 5
L 4 6
L 1 3
Q
*/
Compilation message
rings.cpp: In function 'void Link(int, int)':
rings.cpp:105:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
105 | for (int i = 0; i < cand.size(); i++)
| ~~^~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
588 KB |
Output is correct |
| 2 |
Correct |
371 ms |
844 KB |
Output is correct |
| 3 |
Correct |
560 ms |
844 KB |
Output is correct |
| 4 |
Incorrect |
1 ms |
712 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
2 ms |
1228 KB |
Execution killed with signal 11 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
588 KB |
Output is correct |
| 2 |
Correct |
371 ms |
844 KB |
Output is correct |
| 3 |
Correct |
560 ms |
844 KB |
Output is correct |
| 4 |
Incorrect |
1 ms |
712 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
588 KB |
Output is correct |
| 2 |
Correct |
371 ms |
844 KB |
Output is correct |
| 3 |
Correct |
560 ms |
844 KB |
Output is correct |
| 4 |
Incorrect |
1 ms |
712 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
588 KB |
Output is correct |
| 2 |
Correct |
371 ms |
844 KB |
Output is correct |
| 3 |
Correct |
560 ms |
844 KB |
Output is correct |
| 4 |
Incorrect |
1 ms |
712 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
