mirror of
https://git.sb/baoshuo/OI-codes.git
synced 2024-12-12 00:06:27 +00:00
48 lines
1.0 KiB
C++
48 lines
1.0 KiB
C++
#include <bits/stdc++.h>
|
|
|
|
using namespace std;
|
|
|
|
int n, m, k, ans, l, a[1005], d[1005], c[1005][1005], f[1005];
|
|
bool v[1005][1005];
|
|
|
|
int dfs(int x) {
|
|
if (f[x]) {
|
|
return f[x];
|
|
}
|
|
for (int i = 1; i <= c[x][0]; i++) {
|
|
f[x] = max(f[x], dfs(c[x][i]));
|
|
}
|
|
return ++f[x];
|
|
}
|
|
|
|
int main() {
|
|
cin >> n >> m;
|
|
for (int i = 1; i <= m; i++) {
|
|
cin >> a[0];
|
|
for (int j = 1; j <= a[0]; j++) {
|
|
cin >> a[j];
|
|
}
|
|
l = 1;
|
|
for (int j = a[1]; j < a[a[0]]; j++) {
|
|
if (a[l] == j) {
|
|
l++;
|
|
}
|
|
else {
|
|
for (int k = 1; k <= a[0]; k++) {
|
|
if (!v[a[k]][j]) {
|
|
int t = a[k];
|
|
c[t][0]++;
|
|
c[t][c[t][0]] = j;
|
|
v[t][j] = 1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
for (int i = 1; i <= n; i++) {
|
|
ans = max(ans, dfs(i));
|
|
}
|
|
cout << ans << endl;
|
|
return 0;
|
|
}
|