#include <bits/stdc++.h>
using namespace std;
const int MAXN = 500005;
int N, K;
int A[MAXN], B[MAXN];
int ed[MAXN];
vector<int> chi[MAXN];
bool chk[MAXN], col[MAXN];
vector<int> cyc;
int nex[2 * MAXN];
int ans;
int dfs(int x) {
//cout << "dfs(" << x << ")\n";
chk[x] = true;
int go = 0;
for(auto a : chi[x]) go = max(go, dfs(a));
if(x == 1) go = K - 1;
else if(go-- == 0) {
ans++;
go = K - 1;
}
return go;
}
void searchgraph(int x) {
//cout << "searchgraph(" << x << ")\n";
for(; !chk[x]; x = ed[x]) chk[x] = true;
for(cyc.clear(); cyc.empty() || cyc[0] != x; x = ed[x]) cyc.push_back(x);
int go = 0;
bool done = true;
for(int i = 0; i < cyc.size(); i++) {
for(auto a : chi[cyc[i]]) if(a != cyc[(i + cyc.size() - 1) % cyc.size()]) go = max(go, dfs(a));
//cout << "go = " << go << "\n";
if(go-- > 0) col[i] = true;
else done = col[i] = false;
}
for(int i = 0; i < go; i++) col[i] = true;
/*for(int i = 0; i < cyc.size(); i++) cout << cyc[i] << " ";
cout << "\n";
for(int i = 0; i < cyc.size(); i++) cout << int(col[i]) << " ";
cout << "\n";
cout << int(done) << "\n";*/
if(done) return;
if(cyc.size() <= K) {
ans++;
return;
}
for(nex[0] = K; col[nex[0] % cyc.size()]; nex[0]++);
for(int i = 1; i < cyc.size() * 2; i++) {
nex[i] = nex[i - 1];
if(nex[i] < i + K) for(nex[i]++; col[nex[i] % cyc.size()]; nex[i]++);
}
//for(int i = 0; i < cyc.size(); i++) cout << nex[i] << " ";
//cout << "\n";
int mn = 0;
for(int t = nex[0]; t < cyc.size() + nex[0]; t = nex[t]) mn++;
for(int i = 0; i < K; i++) {
int cnt = 0;
for(int t = i; t < cyc.size() + i; t = nex[t]) cnt++;
mn = min(mn, cnt);
}
ans += mn;
}
int main() {
ios::sync_with_stdio(0); cin.tie(0);
cin >> N >> K;
for(int i = 0; i < N; i++) cin >> A[i] >> B[i];
for(int i = 0; i < N; i++) {
ed[A[i]] = B[i];
chi[B[i]].push_back(A[i]);
}
for(int i = 1; i <= N; i++) if(!chk[i]) searchgraph(i);
cout << ans;
return 0;
}
Compilation message
link.cpp: In function 'void searchgraph(int)':
link.cpp:34:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0; i < cyc.size(); i++) {
~~^~~~~~~~~~~~
link.cpp:47:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
if(cyc.size() <= K) {
~~~~~~~~~~~^~~~
link.cpp:52:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 1; i < cyc.size() * 2; i++) {
~~^~~~~~~~~~~~~~~~
link.cpp:59:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int t = nex[0]; t < cyc.size() + nex[0]; t = nex[t]) mn++;
~~^~~~~~~~~~~~~~~~~~~~~
link.cpp:62:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int t = i; t < cyc.size() + i; t = nex[t]) cnt++;
~~^~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
12 ms |
12152 KB |
Output is correct |
2 |
Incorrect |
12 ms |
12152 KB |
Output isn't correct |
3 |
Correct |
13 ms |
12152 KB |
Output is correct |
4 |
Correct |
14 ms |
12280 KB |
Output is correct |
5 |
Incorrect |
15 ms |
12380 KB |
Output isn't correct |
6 |
Correct |
23 ms |
13528 KB |
Output is correct |
7 |
Correct |
33 ms |
14584 KB |
Output is correct |
8 |
Incorrect |
43 ms |
15608 KB |
Output isn't correct |
9 |
Correct |
66 ms |
18552 KB |
Output is correct |
10 |
Correct |
67 ms |
17140 KB |
Output is correct |
11 |
Correct |
98 ms |
21488 KB |
Output is correct |
12 |
Correct |
142 ms |
21116 KB |
Output is correct |
13 |
Incorrect |
179 ms |
26104 KB |
Output isn't correct |
14 |
Correct |
226 ms |
26104 KB |
Output is correct |
15 |
Correct |
266 ms |
29940 KB |
Output is correct |
16 |
Correct |
353 ms |
31240 KB |
Output is correct |
17 |
Correct |
347 ms |
34060 KB |
Output is correct |
18 |
Incorrect |
446 ms |
35016 KB |
Output isn't correct |
19 |
Correct |
390 ms |
35316 KB |
Output is correct |
20 |
Correct |
386 ms |
36384 KB |
Output is correct |
21 |
Incorrect |
385 ms |
37908 KB |
Output isn't correct |
22 |
Correct |
397 ms |
36980 KB |
Output is correct |
23 |
Correct |
396 ms |
36592 KB |
Output is correct |
24 |
Correct |
391 ms |
36716 KB |
Output is correct |
25 |
Correct |
391 ms |
36212 KB |
Output is correct |