1 #include<cstdio>
2 #include<cstring>
3 #include<iostream>
4 #include<string>
5 #include<vector>
6 #include<queue>
7 #include<stack>
8 #include<set>
9 #include<algorithm>
10 using namespace std;
11 #define N 500001
12 stack<int>Sta;
13 queue<int>Que;
14 struct edge
15 {
16 int u,v,next;
17 }edge1[N],edge2[N];
18 bool isBar[N],inStack[N];
19 int low[N],dfn[N],belong[N],money[N],newMoney[N],cnt,Time,start;
20 int maxMoney[N],head[N],head2[N];
21
22 void add(int u, int v, int id)
23 {
24 edge1[id].u = u;
25 edge1[id].v = v;
26 edge1[id].next = head[u];
27 head[u] = id;
28 }
29
30 void add2(int u, int v, int id)
31 {
32 edge2[id].u = u;
33 edge2[id].v = v;
34 edge2[id].next = head2[u];
35 head2[u] = id;
36 }
37 void Tarjan(int s)
38 {
39 dfn[s] = low[s] = ++Time;
40 Sta.push(s);
41 inStack[s] = true;
42 for(int u = head[s]; ~u; u = edge1[u].next)
43 {
44 int v = edge1[u].v;
45 if(dfn[v] == 0){
46 Tarjan(v);
47 low[s] = min(low[s], low[v]);
48 }
49 else if(inStack[v] == true){
50 low[s] = min(low[s], dfn[v]);
51 }
52 }
53 if(dfn[s] == low[s])
54 {
55 cnt ++;
56 while(!Sta.empty()){
57 int temp = Sta.top(); Sta.pop();
58 belong[temp] = cnt;
59 newMoney[cnt] += money[temp];
60 inStack[temp] = false;
61 if(temp == s) break;
62 }
63 }
64 }
65
66 int spfa()
67 {
68 int ans = 0;
69 Que.push(start);
70 memset(maxMoney,0,sizeof(maxMoney));
71 maxMoney[start] = newMoney[start];
72 while(!Que.empty())
73 {
74 int now = Que.front(); Que.pop();
75 for(int u = head2[now]; ~u; u = edge2[u].next)
76 {
77 int v = edge2[u].v;
78 if(maxMoney[now] + newMoney[v] > maxMoney[v])
79 {
80 maxMoney[v] = maxMoney[now] + newMoney[v];
81 Que.push(v);
82 }
83 if(isBar[v]) ans = max(ans, maxMoney[v]);
84 }
85 }
86 return ans;
87 }
88
89 int main()
90 {
91 int n,m,a,b,s,p;
92 scanf("%d%d",&n,&m);
93 memset(head,-1,sizeof(head));
94 for (int i = 0; i < m; i++) {
95 /* code */
96 scanf("%d%d",&a, &b);
97 add(a,b,i+1);
98 }
99 for (int i = 1; i <= n; i++) {
100 /* code */
101 scanf("%d",&money[i]);
102 }
103 scanf("%d%d",&s,&p);
104 memset(inStack,false,sizeof(inStack));
105 memset(newMoney,0,sizeof(newMoney));
106 memset(isBar,false,sizeof(isBar));
107 memset(dfn,0,sizeof(dfn));
108 cnt = Time = 0;
109 for(int i = 1; i <= n; i++) if(dfn[i] == 0) Tarjan(i);
110 if(cnt == 1) {printf("%d",newMoney[cnt]);return 0;}
111 for(int i=0;i<p;i++)
112 {
113 scanf("%d", &a);
114 isBar[belong[a]] = true;
115 }
116 start = belong[s];
117 memset(head2,-1,sizeof(head2));
118 int kkk = 0;
119 for(int i =1; i <= n; i ++)
120 {
121 for(int u = head[i]; ~u; u = edge1[u].next){
122 int v = edge1[u].v;
123 if(belong[i] != belong[v]){
124 add2(belong[i],belong[v],++kkk);
125 }
126 }
127 }
128
129 int ans = spfa();
130 printf("%d", ans);
131 }
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