hdu 3191+hdu 1688(最短路+次短路）

#include<iostream>
#include<cstdio>
#include<vector>
#include<queue>
using namespace std;
const int MAXN=1000+10;
const int inf=1<<30;
struct Edge{
int v,w;
};
vector<Edge>vet[MAXN];
struct Node{
int v,dist;
int mark;
bool operator < (const Node &p)const {
return p.dist<dist;
}
};
int dist[MAXN][3];
int dp[MAXN][3];
bool visited[MAXN][3];
int n,m,s,e;

void Dijkstra(int start,int end){
for(int i=1;i<=n;i++){
dist[i][1]=dist[i][2]=inf;
}
memset(visited,false,sizeof(visited));
memset(dp,0,sizeof(dp));
dist[start][1]=0;
dp[start][1]=1;
priority_queue<Node>Q;
Node p,q;
p.dist=0,p.mark=1,p.v=start;
Q.push(p);
while(!Q.empty()){
p=Q.top();
Q.pop();
if(visited[p.v][p.mark])continue;
visited[p.v][p.mark]=true;
for(int i=0;i<vet[p.v].size();i++){
int v=vet[p.v][i].v;
int w=vet[p.v][i].w;
if(!visited[v][1]&&p.dist+w<dist[v][1]){
if(dist[v][1]!=inf){
dist[v][2]=dist[v][1];
dp[v][2]=dp[v][1];
q.v=v,q.dist=dist[v][2],q.mark=2;
Q.push(q);
}
dist[v][1]=p.dist+w;
dp[v][1]=dp[p.v][p.mark];
q.dist=dist[v][1],q.v=v,q.mark=1;
Q.push(q);
}else if(!visited[v][1]&&p.dist+w==dist[v][1]){
dp[v][1]+=dp[p.v][p.mark];
}else if(!visited[v][2]&&p.dist+w<dist[v][2]){
dist[v][2]=p.dist+w;
dp[v][2]=dp[p.v][p.mark];
q.v=v,q.dist=dist[v][2],q.mark=2;
Q.push(q);
}else if(!visited[v][2]&&p.dist+w==dist[v][2]){
dp[v][2]+=dp[p.v][p.mark];
}
}
}
}

int main(){
int _case;
scanf("%d",&_case);
while(_case--){
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++)vet[i].clear();
for(int i=1;i<=m;i++){
int u,v,w;
scanf("%d%d%d",&u,&v,&w);
Edge p;
p.v=v,p.w=w;
vet[u].push_back(p);
}
scanf("%d%d",&s,&e);
Dijkstra(s,e);
if(dist[e][1]+1==dist[e][2]){
printf("%d\n",dp[e][1]+dp[e][2]);
}else
printf("%d\n",dp[e][1]);
}
return 0;
}