HDU 2544 最短路——简单的模板题 dijkstra

  1 #include<cstdio>
  2 #include<cstring>
  3 #include<cstdlib>
  4 
  5 using namespace std;
  6 
  7 const int Max = 100000001;
  8 
  9 struct N
 10 {
 11     int v,w;
 12     N *next;
 13 }*head[110];
 14 
 15 void init(int n)
 16 {
 17     for(int i = 1;i <= n; i++)
 18     {
 19         head[i] = (struct N *)malloc(sizeof(struct N));
 20         head[i]->v = head[i]->w  = -1;
 21         head[i]->next = NULL;
 22     }
 23 }
 24 
 25 void link(int u,int v,int w)
 26 {
 27     N *p1,*p2,*p;
 28     for(p1 = head[u],p2 = head[u]->next; p2 != NULL; p1 = p1->next,p2 = p2->next)
 29     {
 30         if(p2->v == v)
 31         {
 32             if(p2->w > w)
 33                 p2->w = w;
 34             return;
 35         }
 36         if(p1->v < v && v < p2->v)
 37         {
 38             p = (struct N *)malloc(sizeof(struct N));
 39             p->v = v;
 40             p->w = w;
 41             p->next = p1->next;
 42             p1->next = p;
 43             return;
 44         }
 45     }
 46     p = (struct N *)malloc(sizeof(struct N));
 47     p->v = v;
 48     p->w = w;
 49     p->next = NULL;
 50     p1->next = p;
 51     return;
 52 }
 53 
 54 int mark[1000];
 55 
 56 void find(int n)
 57 {
 58     int q[10001],t;
 59     int s,e,i;
 60     for(i = 1;i <= n; i++)
 61         mark[i] = Max;
 62     N *p;
 63     for(s = 0,e = 0,p = head[1]->next; p != NULL; p = p->next)
 64     {
 65         q[e++] = p->v;
 66         mark[p->v] = p->w;
 67        
 68     }
 69     while(s != e)
 70     {
 71         t = q[s];
 72         s++;
 73         for(p = head[t]->next; p != NULL; p = p->next)
 74         {
 75             if(mark[t] + p->w < mark[p->v])
 76             {
 77                 mark[p->v] = mark[t] + p->w;
 78                 q[e++] = p->v;
 79              
 80             }
 81         }
 82     }
 83 }
 84 
 85 int main()
 86 {
 87     int n,m,i,u,v,w,t;
 88     while(scanf("%d %d",&n,&m) != EOF && (m||n) )
 89     {
 90         init(n);
 91         for(i = 0;i < m;i++)
 92         {
 93             scanf("%d %d %d",&u,&v,&w);
 94             link(v,u,w);
 95             link(u,v,w);
 96         }
 97         find(n);
 98         printf("%d\n",mark[n]);
 99     }
100     return 0;
101 }