```cpp
inline node mul(node a, node b)
{
node c;
memset(c.a, -INF, sizeof(c.a));
for (int i = 1; i <= 3; ++ i)
for (int j = 1; j <= 3; ++ j)
for (int k = 1; k <= 3; ++ k)
c.a[i][j] = max(a.a[i][k] * b.a[k][j], c.a[i][j]);
return c;
}
```
这个函数中的$a.a[i][k] * b.a[k][j]$应为$a.a[i][k] + b.a[k][j]$吧……
by Nickel_Angel @ 2019-07-13 19:21:29
@[Nickel_Angel](/space/show?uid=121638) 谢谢大佬
by BCZSX @ 2019-07-13 19:23:30
红名dalao来提问了。。
by Viccc @ 2019-07-13 19:37:36