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OI-codes/AcWing/367/367.cpp

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;
}