洛谷1113 杂务

原题链接

拓扑裸题。（其实可以不用建图就可以搞，不过我太懒了直接上拓扑

#include<cstdio>
using namespace std;
const int N = 1e4 + 10;
const int M = 1e6 + 10;
int fi[N], di[M], ne[M], q[M], v[N], T[N], ru[N], l, n, ma;
inline int re()
{
	int x = 0;
	char c = getchar();
	bool p = 0;
	for (; c < '0' || c > '9'; c = getchar())
		p |= c == '-';
	for (; c >= '0' && c <= '9'; c = getchar())
		x = x * 10 + c - '0';
	return p ? -x : x;
}
inline void add(int x, int y)
{
	di[++l] = y;
	ne[l] = fi[x];
	fi[x] = l;
}
inline int maxn(int x, int y){ return x > y ? x : y; }
void topsort()
{
	int i, head = 0, tail = 0, x, y;
	for (i = 1; i <= n; i++)
		if (!ru[i])
			q[++tail] = i;
	while (head ^ tail)
	{
		x = q[++head];
		T[x] += v[x];
		ma = maxn(ma, T[x]);
		for (i = fi[x]; i; i = ne[i])
		{
			y = di[i];
			T[y] = maxn(T[y], T[x]);
			if (!(--ru[y]))
				q[++tail] = y;
		}
	}
}
int main()
{
	int i, x, y;
	n = re();
	for (i = 1; i <= n; i++)
	{
		y = re();
		v[y] = re();
		for (x = re(); x; x = re())
		{
			add(x, y);
			ru[y]++;
		}
	}
	topsort();
	printf("%d", ma);
	return 0;
}