hdu 4725 The Shortest Path in Nya Graph (SPFA+SLF优化)

#include<stdio.h>
#include<string.h>
#include<queue>
#include<deque>
using namespace std;

const int maxn = 100500;
const int inf = 0x3f3f3f3f;

int t , n , m , c , vis[maxn * 4] , cnt[maxn * 4] , dist[maxn * 4] , cc , a , b;

struct G{
    int head[maxn * 4] , e;
    struct T{
        int u , v , next , cost;
    }edge[maxn * 10];
    void init(){
        memset(head , -1 , sizeof(head));
        e = 0;
    };
    void addedge(int u , int v , int c){
        edge[e].u = u , edge[e].v = v , edge[e].cost = c , edge[e].next = head[u] , head[u] = e ++;
    };
}g;


int relax(int u , int v , int c){
    if(dist[u]  + c < dist[v]){
        dist[v] = dist[u] + c;
        return 1;
    }
    return 0;
}

int SPFA(int src , int des){
    memset(vis , 0 , sizeof(vis));
    memset(cnt , 0 , sizeof(cnt));
    memset(dist , inf , sizeof(dist));
    dist[src] = 0 , vis[src] = 1 , ++ cnt[src];
    deque<int> q;
    q.push_back(src);
    while(!q.empty()){
        int u = q.front();
        int v;
        q.pop_front();
        vis[u] = 0;
        for(int i = g.head[u] ; i != -1 ; i = g.edge[i].next){
            v = g.edge[i].v;
            //printf("i = %d u = %d v = %d\n" , i , u , v);
            if(relax(u , v , g.edge[i].cost) && !vis[v]){
                if(!vis[v]){
                    vis[v] = 1;
                    if(!q.empty()){
                        if(dist[v] > dist[q.front()]){
                            q.push_back(v);
                        }
                        else{
                            q.push_front(v);
                        }
                    }
                    else
                        q.push_back(v);
                }
            }
        }
        vis[u] = 0;
    }
    if(dist[des] == inf) return -2;
    return dist[des];
}

int main(){
    int a;
    scanf("%d" , &t);
    for(int cases = 1 ; cases <= t ; cases ++){
        g.init();
        scanf("%d%d%d" , &n , &m , &c);
        for(int i = 1 ; i <= n ; i ++){
            scanf("%d" , &a);
            g.addedge(i , n + 2 * a , 0);
            g.addedge(n + 2 * a - 1 , i , 0);
        }
        for(int i = 1 ; i < n ; i ++){
            g.addedge(n + 2 * i , n + 2 * (i + 1) - 1 , c);
            g.addedge(n + 2 * (i + 1) , n + 2 * i - 1 , c);
        }
        for(int i = 0 ; i < m ; i ++){
            scanf("%d %d %d", &a , &b , &cc);
            g.addedge(a , b , cc);
            g.addedge(b , a , cc);
        }
        int temp = SPFA(1 , n);
        printf("Case #%d: " , cases);
        if(temp < 0 || temp == inf) printf("-1\n");
        else printf("%d\n" , temp);
    }
}