TLE #8,#9

#include<iostream>
#include<cstdio>
#include<stack>
#include<cstring>
#include<queue>
using namespace std;
typedef long long ll;
const ll MAXN = 5e5, MAXM = 5e5;
ll n, m, tot = 0, s, k, dfsTime = 0, sccCnt = 0, ans = 0;
ll u[MAXM + 5], v[MAXM + 5], head[MAXN + 5], a[MAXN + 5], pre[MAXN + 5], low[MAXN + 5], sccNo[MAXN + 5], money[MAXN + 5], rob[MAXN + 5];
struct Edge {
	ll to, nxt;
} edge[MAXM + 5];
stack<ll> st;
bool vis[MAXN + 5];
inline void addEdge(ll u, ll v) {
	edge[++tot].to = v;
	edge[tot].nxt = head[u];
	head[u] = tot;
}
void tarjan(ll u, ll father) {
	st.push(u);
	pre[u] = low[u] = ++dfsTime;
	for (ll i = head[u]; i; i = edge[i].nxt) {
		ll v = edge[i].to;
		if (v == father) {
			continue;
		}
		if (!pre[v]) {
			tarjan(v, u);
			low[u] = min(low[u], low[v]);
		} else if (!sccNo[v]) {
			low[u] = min(low[u], pre[v]);
		}
	}
	if (pre[u] == low[u]) {
		sccCnt++;
		while (1) {
			ll x = st.top();
			st.pop();
			sccNo[x] = sccCnt;
			if (x == u) {
				break;
			}
		}
	}
}
void spfa(ll s) {
	queue<ll> q;
	q.push(s);
	vis[s] = 1;
	rob[s] = money[s];
	while (!q.empty()) {
		ll u = q.front();
		q.pop();
		vis[u] = 0;
		for (ll i = head[u]; i; i = edge[i].nxt) {
			ll v = edge[i].to, w = money[v];
			if (rob[v] < rob[u] + w) {
				rob[v] = rob[u] + w;
				if (!vis[v]) {
					q.push(v);
					vis[v] = 1;
				}
			}
		}
	}
}
int main() {
	scanf("%lld%lld", &n, &m);
	for (ll i = 1; i <= m; i++) {
		scanf("%lld%lld", &u[i], &v[i]);
		addEdge(u[i], v[i]);
	}
	for (ll i = 1; i <= n; i++) {
		scanf("%lld", &a[i]);
	}
	scanf("%lld%lld", &s, &k);
	tarjan(s, 0);
	tot = 0;
	memset(head, 0, sizeof(head));
	memset(edge, 0, sizeof(edge));
	for (ll i = 1; i <= m; i++) {
		if (sccNo[u[i]] != sccNo[v[i]]) {
			addEdge(sccNo[u[i]], sccNo[v[i]]);
			// addEdge(sccNo[v[i]], sccNo[u[i]]);
		}
	}
	for (ll i = 1; i <= n; i++) {
		money[sccNo[i]] += a[i];
	}
	spfa(sccNo[s]);
	while (k--) {
		ll p;
		scanf("%lld", &p);
		ans = max(ans, rob[sccNo[p]]);
	}
	printf("%lld\n", ans);
	return 0;
}

我太菜了，看不出来哪里有问题，求助！（好像别人用spfa都不会T）……