hdu2544（自己实现优先队列）

hdu2544  dij水题，用来测试自己实现优先队列对不对

 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #include <algorithm>
 #include <iostream>
 #include <queue>
 #include <stack>
 #include <vector>
 #include <map>
 #include <set>
 #include <string>
 #include <math.h>
 using namespace std;
 #pragma warning(disable:4996)
 typedef long long LL;
 const int INF =  << ;
 const int N =  + ;
 int len;
 struct node
 {
     int v, cost;
     int next;
 }g[+];
 int head[N], e;
 int dist[N];
 bool vis[N];
 void init(int n)
 {
     for (int i = ; i <= n; ++i)
         head[i] = -;
     e = ;
 }
 void addEdge(int u, int v, int c)
 {
     g[e].v = v;
     g[e].cost = c;
     g[e].next = head[u];
     head[u] = e++;
 }
 struct node2
 {
     int v, dist;
     bool operator<(const node2&rhs)const
     {
         return dist > rhs.dist;
     }
 }q[];

 void push(node2 tmp)//在队尾加入一个元素，只要调整到父亲结点不大于自己即可
 {
     int adjustIndex = ++len;
     for (int i = adjustIndex / ; i >= ; i /= )
     {
         if (q[i].dist < tmp.dist)
             break;
         q[adjustIndex] = q[i];
         adjustIndex = i;
     }
     q[adjustIndex] = tmp;
 }

 node2 get()
 {
     node2 ret = q[];//得到队首元素
     node2 tmp = q[len--];//将队尾元素放到队首
     int adjustIndex = ;
     //调整成一个小顶堆
     for (int i = adjustIndex * ; i <= len; i = i * )
     {
         if (i < len && q[i].dist > q[i + ].dist)
             i++;
         if (tmp.dist < q[i].dist)
             break;
         q[adjustIndex] = q[i];
         adjustIndex = i;
     }
     q[adjustIndex] = tmp;
     return ret;
 }

 void dij(int n)
 {
     //priority_queue<node2> q;
     for (int i = ; i <= n; ++i)
     {
         dist[i] = INF;
         vis[i] = false;
     }
     len = ;
     dist[] = ;
     node2 cur, tmp;
     cur.v = ;
     cur.dist = ;
     //q.push(cur);
     push(cur);
     while (len!=)
     {
         cur = get();
         //cur = q.top();
         //q.pop();
         int x = cur.v;
         if (vis[x]) continue;
         vis[x] = true;
         for (int i = head[x]; i != -; i = g[i].next)
         {
             int v = g[i].v;
             tmp.v = v;
             if (dist[v] > dist[x] + g[i].cost)
             {
                 tmp.dist = dist[v] = dist[x] + g[i].cost;
                 //q.push(tmp);
                 push(tmp);
             }
         }

     }
 }
 int main()
 {
     int n, m, a, b, c, i;
     while (scanf("%d%d", &n, &m) ,n)
     {
         init(n);
         for (i = ; i < m; ++i)
         {
             scanf("%d%d%d", &a, &b, &c);
             addEdge(a, b, c);
             addEdge(b, a, c);
         }
         dij(n);
         printf("%d\n", dist[n]);
     }
 }