tarjan缩点后，直接拓扑排序 + dp
by Nuisdete @ 2020-08-11 18:56:50
你是求思想的？
by wd_dw @ 2020-08-11 18:56:53
这……我还没学过tarjan QAQ
by X_Chara @ 2020-08-11 19:05:35
@[louis_11](/user/202791)
by X_Chara @ 2020-08-11 19:07:18
@[代号_柒](/user/246188) 那数据多大？
by Nuisdete @ 2020-08-11 21:01:18
```cpp
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2005;
int n, ans;
char a[MAXN];
bitset<MAXN> G[MAXN];
int main()
{
scanf("%d", &n);
for(int i = 1; i <= n; i++)
{
scanf("%s", a + 1);
for(int j = 1; j <= n; j++)
G[i][j] = a[j] == '1';
G[i][i] = 1;
}
for(int i = 1; i <= n; i++)
for(int j = 1; j <= n; j++)
if (G[j][i])
G[j] |= G[i];
for(int i = 1; i <= n; i++)
ans += G[i].count();
printf("%d", ans);
return 0;
}
```
by X_Chara @ 2020-08-13 14:44:59
做出来了 @[louis_11](/user/202791)
by X_Chara @ 2020-08-13 14:45:10