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 1 #include<iostream>
 2 #include<cstdio>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<cmath>
 6 #include<queue>
 7 #include<vector>
 8 #include<map>
 9 #include<set>
10 #include<stack>
11 using namespace std;
12 int read(){
13   int x=0,f=1;char s=getchar();
14   while(s<'0'||s>'9'){if(s=='-') f=-1;s=getchar();}
15   while(s>='0'&&s<='9'){x=x*10+s-'0';s=getchar();}
16   return x*f;
17 }
18 queue<int>q;
19 const int maxn=1007;
20 const int maxm=20007;
21 const int INF=0x7f7f7f7f;
22 int n,ml,md,num;
23 int head[maxn],cnt[maxn],d[maxn];
24 bool flag;
25 bool inq[maxn];
26 struct Edge{
27   int nxt,to,dis;
28 }edge[maxm<<1];
29 void add(int from,int to,int dis){
30   edge[++num].nxt=head[from];
31   edge[num].to=to;
32   edge[num].dis=dis;
33   head[from]=num;
34 }
35 void spfa(int x){
36   memset(inq,false,sizeof(inq));
37   memset(d,INF,sizeof(d));
38   memset(cnt,0,sizeof(cnt));
39   d[x]=0;inq[x]=true;q.push(x);
40   while(!q.empty()){
41     int u=q.front();inq[u]=false;q.pop();
42     for(int i=head[u];i;i=edge[i].nxt){
43       int v=edge[i].to;
44       if(d[v]>d[u]+edge[i].dis){
45         d[v]=d[u]+edge[i].dis;
46         if(!inq[v]){
47           cnt[v]++;inq[v]=true;q.push(v);
48           if(cnt[v]>n){
49             cout<<-1<<endl;flag=true;return;
50           }
51         } 
52       }
53     }
54   }
55 }
56 int main(){
57   //freopen("a.in","r",stdin);
58   n=read();ml=read();md=read();
59   for(int i=1;i<=ml;i++){
60     int u,v,w;u=read();v=read();w=read();
61     add(u,v,w);
62   }
63   for(int i=1;i<=md;i++){
64     int u,v,w;u=read();v=read();w=read();
65     add(v,u,-w);
66   }
67   for(int i=1;i<=n;i++) add(0,i,0);
68   for(int i=2;i<=n;i++) add(i,i-1,0);
69   spfa(0);
70   if(!flag){
71     spfa(1);
72     if(d[n]==INF) cout<<-2<<endl;
73     else cout<<d[n]<<endl;
74   }
75   return 0;
76 }

 

posted @ 2018-11-06 14:58  lcan  阅读(231)  评论(0)    收藏  举报