mirror of
https://git.sb/baoshuo/OI-codes.git
synced 2024-11-05 14:18:47 +00:00
74 lines
1.4 KiB
C++
74 lines
1.4 KiB
C++
|
#include <iostream>
|
||
|
#include <stack>
|
||
|
#include <vector>
|
||
|
|
||
|
using std::cin;
|
||
|
using std::cout;
|
||
|
using std::endl;
|
||
|
|
||
|
// Limits
|
||
|
const int N = 105;
|
||
|
|
||
|
int n, x, ans1, ans2;
|
||
|
std::vector<int> g[N];
|
||
|
int din[N], dout[N]; // 图的入度、出度
|
||
|
|
||
|
// Tarjan
|
||
|
int cnt, dfn[N], low[N];
|
||
|
int scc_cnt, id[N];
|
||
|
std::stack<int> st;
|
||
|
bool vis[N];
|
||
|
|
||
|
void tarjan(int u) {
|
||
|
dfn[u] = low[u] = ++cnt;
|
||
|
st.push(u);
|
||
|
vis[u] = true;
|
||
|
for (int v : g[u]) {
|
||
|
if (!dfn[v]) {
|
||
|
tarjan(v);
|
||
|
low[u] = std::min(low[u], low[v]);
|
||
|
} else if (vis[v]) {
|
||
|
low[u] = std::min(low[u], dfn[v]);
|
||
|
}
|
||
|
}
|
||
|
if (dfn[u] == low[u]) {
|
||
|
scc_cnt++;
|
||
|
int v;
|
||
|
do {
|
||
|
v = st.top();
|
||
|
st.pop();
|
||
|
id[v] = scc_cnt;
|
||
|
vis[v] = false;
|
||
|
} while (v != u);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
int main() {
|
||
|
cin >> n;
|
||
|
for (int i = 1; i <= n; i++) {
|
||
|
while (cin >> x, x) {
|
||
|
g[i].push_back(x);
|
||
|
}
|
||
|
}
|
||
|
for (int i = 1; i <= n; i++) {
|
||
|
if (!dfn[i]) {
|
||
|
tarjan(i);
|
||
|
}
|
||
|
}
|
||
|
for (int i = 1; i <= n; i++) {
|
||
|
for (int v : g[i]) {
|
||
|
if (id[i] != id[v]) {
|
||
|
dout[id[i]]++;
|
||
|
din[id[v]]++;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
for (int i = 1; i <= scc_cnt; i++) {
|
||
|
if (!din[i]) ans1++;
|
||
|
if (!dout[i]) ans2++;
|
||
|
}
|
||
|
cout << ans1 << endl
|
||
|
<< (scc_cnt == 1 ? 0 : std::max(ans1, ans2)) << endl;
|
||
|
return 0;
|
||
|
}
|