HDU 4725 The Shortest Path in Nya Graph priority_queue + spfa

#include <stdio.h>#include <string.h>#include <iostream>#include <queue>#include <set>#include <vector>#include<cmath>#include<algorithm>#include<stdlib.h>#define N 300050#define inf 100000000#define Mid(x,y) ((x+y)>>1)#define L(id) tree[id].ch[0]#define R(id) tree[id].ch[1]#define Father(id) tree[id].fa#define Size(id) tree[id].size#define Val(id) tree[id].valusing namespace std;struct Edge{int from, to, dis, nex;}edge[200050+N*2];int head[N], edgenum;void add(int u, int v, int d){Edge E={u,v,d,head[u]};edge[edgenum] = E;head[u] = edgenum++;}int dis[N];int n, m, c;struct node{int pos, dis;bool operator<(const node&a)const{return a.dis < dis;}node(int a=0,int b=0):pos(a),dis(b){}};int spfa(int s, int t){n*=3; n+=10;for(int i = 1; i <= n; i++)dis[i] = inf;dis[s] = 0;priority_queue<node>q; q.push(node(s,0));while(!q.empty()){node G = q.top(); q.pop(); if(G.pos == t)return G.dis;for(int i = head[G.pos]; ~i; i = edge[i].nex){int v = edge[i].to;if(dis[v] > dis[G.pos]+edge[i].dis){dis[v] = dis[G.pos]+edge[i].dis;q.push(node(v,dis[v]));}}}return -1;}void init(){memset(head, -1, sizeof head); edgenum = 0;}int main(){int que, u, v, i, j, T, Cas = 1; scanf("%d",&T);while(T--){scanf("%d %d %d",&n,&m,&c);init();for(i = 1; i <= n; i++){scanf("%d",&u);add(i, n + 2*u - 1, 0);add(n + 2*u, i, 0);}for(i = 1; i <  n; i++)add(n + 2*i-1, n + 2*(i+1), c), add(n + 2*(i+1)-1, n+2*i, c);while(m--){scanf("%d %d %d",&u,&v,&c);add(u,v,c);add(v,u,c);}printf("Case #%d: %d\n", Cas++, spfa(1,n));}return 0;}