LightOJ 1074 Extended Traffic SPFA 消负环

#include<cstdio>
#include<cstring>
#include<queue>
#include<cstdlib>
#include<algorithm>
#include<vector>
#include<cmath>
using namespace std;
typedef long long LL;
const int N=200+5;
const int INF=0x7fffffff;
struct Edge{
int v;
LL w;
int next;
bool operator<(const Edge &e)const{
return w>e.w;
}
}edge[N*N];
int head
,val
,tot,n,m,p;
LL d
;
void add(int u,int v,LL w){
edge[tot].v=v;
edge[tot].w=w;
edge[tot].next=head[u];
head[u]=tot++;
}
bool inq
;
queue<int>q;
int cnt
;
bool c
;
void dfs(int u){
c[u]=1;
for(int i=head[u];~i;i=edge[i].next)
if(!c[edge[i].v])dfs(edge[i].v);
}
void spfa(int s){
for(int i=1;i<=n;++i)
c[i]=cnt[i]=inq[i]=0,d[i]=INF;
q.push(s),cnt[s]=1,inq[s]=1,d[s]=0;
while(!q.empty()){
int u=q.front();
q.pop();
inq[u]=0;
if(c[u])continue;
for(int i=head[u];~i;i=edge[i].next){
int v=edge[i].v;
if(c[v])continue;
if(d[v]>d[u]+edge[i].w){
d[v]=d[u]+edge[i].w;
if(inq[v])continue;
q.push(v);
++cnt[v];
inq[v]=1;
if(cnt[v]>n)dfs(v);
}
}
}
}
int main(){
int T,cas=0;
scanf("%d",&T);
while(T--){
scanf("%d",&n);
for(int i=1;i<=n;++i)scanf("%d",&val[i]);
scanf("%d",&m);
memset(head,-1,sizeof(head)),tot=0;
for(int i=0;i<m;++i){
int u,v;
scanf("%d%d",&u,&v);
LL w=(val[v]-val[u]);
w=w*w*w;
add(u,v,w);
}
spfa(1);
scanf("%d",&p);
printf("Case %d:\n",++cas);
for(int i=1;i<=p;++i){
int u;
scanf("%d",&u);
if(c[u]||d[u]==INF||d[u]<3)printf("?\n");
else printf("%d\n",d[u]);
}
}
return 0;
}