标签：最短路

HDU Today

6
xiasha westlake
xiasha station 60
xiasha ShoppingCenterofHangZhou 30
station westlake 20
ShoppingCenterofHangZhou supermarket 10
xiasha supermarket 50
supermarket westlake 10
-1

50


Hint:
The best route is:
xiasha->ShoppingCenterofHangZhou->supermarket->westlake


虽然偶尔会迷路，但是因为有了你的帮助
**和**从此还是过上了幸福的生活。

――全剧终――

/*dijkstra*/
#include<stdio.h>
#include<string.h>
#define INF 0x3f3f3f
#define min(a, b)  a>b?b:a
using namespace std;
const int mx = 160;
int map[mx][mx],d[mx],vis[mx];
int n,start,end;
char str[mx][33];
int find(char a[])
{
    for(int i = 1; i <= n; i ++)
        if(strcmp(a,str[i]) == 0)
        return i;
    strcpy(str[++n], a);
    return n;
}
void dijkstra(int s)
{
    int i,j;
    for(i = 1; i <= n; i++)
    {
        vis[i] = 0;
        d[i] = map[s][i];
    }
    vis[s] = 1;
    for( i = 1; i < n; i++)
    {
        int min = INF,k = s;
        for( j = 1; j <= n; j++)
        if(!vis[j] && d[j] < min)
        {
            min = d[j];
            k = j;
        }
        vis[k] = 1;
        for( j = 1; j <= n; j++)
        if(!vis[j])
        d[j] = min(d[j], d[k]+map[k][j]);
    }
    if(d[end]!=INF)
    printf("%d\n",d[end]);
    else if(start == end)
    printf("0\n");
    else
    printf("-1\n");
}
int main()
{
    int i,j,k,c;
    char s[33],e[33];
    while(scanf("%d",&c)!=EOF,c!=-1)
    {
        n = 0;
        int a,b,t;
        scanf("%s",s);    start = find(s);    
        scanf("%s",s);    end = find(s);
        for(i = 0; i < 150; i++)
        for(j = 0; j < 150; j++)
            map[i][j] = INF;
        while(c--)
        {
            scanf("%s",s);
            a = find(s);        
            scanf("%s",s);
            b = find(s);        
            scanf("%d",&t);
            if(map[a][b] > t)
            map[a][b] = map[b][a] = t;        
        }
        dijkstra(start);
    }
}

/*spfa*/
#include<stdio.h>
#include<string.h>
#include<queue>
#include<algorithm>
#define INF 0x3f3f3f3f
using namespace std;
const int mx =1600;
int dis[mx],vis[mx],head[mx],edgenum;
char str[mx][mx];
int start, ed,n;//为什么用end老是CE..... 
int find(char s[])
{
      for(int i = 1; i <= n;i++)
      if(strcmp(s,str[i])==0)
            return i;
      strcpy(str[++n],s);
      return n;
}
struct node{
      int a,b,val,next;
}p[211000];
void add(int u,int v,int w)
{
      node E = {u, v, w, head[u]};
      p[edgenum] = E;
      head[u]=edgenum++;
}
void spfa(int sx,int en)
{
      queue<int> q;
      memset(dis,0x3f,sizeof(dis));
      memset(vis,0,sizeof(vis));      
      dis[sx] = 0;
      vis[sx] = 1;
      q.push(sx);
      while(!q.empty())
      {
            int u = q.front(); q.pop();vis[u] = 0;
            for(int i = head[u];  i!=-1;  i=p[i].next)
            {
                  int v = p[i].b;
                  if(dis[v] > dis[u]+p[i].val)
                  {
                        dis[v] = dis[u]+p[i].val;
                        if(!vis[v])
                        {
                              vis[v] = 1;
                              q.push(v);
                        }
                  }
            }
      }
      if(dis[en] !=INF)
      printf("%d\n",dis[en]);
      else
      printf("-1\n");
}
int main()
{
      int i,j,k,c;
      char s[33],e[33];
      while(scanf("%d",&c)!=EOF,c!=-1)
      {
            n = 0;
            edgenum = 0;
            memset(head, -1, sizeof(head));
            memset(str, '\0', sizeof(str));
            int a,b,t;
            scanf("%s",s); start = find(s);
            scanf("%s",e); ed = find(e);
            while(c--)
            {
                  scanf("%s",s);      a = find(s);
                  scanf("%s",s);      b = find(s);      
                  scanf("%d",&t);
                  add(a,b,t);
                  add(b,a,t);
            }
            spfa(start,ed);
      }
      return 0;
}

/*floyd*/
#include<stdio.h>
#include<string.h>
#define min(a,b) a>b?b:a
#define INF 0x3f3f3f3f
using namespace std;
const int mx = 160; 
int dis[mx][mx];
char str[mx][33];
int n;
int find(char a[])
{
    for(int i=1; i<=n; i++)
    if(strcmp(a,str[i])==0)
        return i;
    strcpy(str[++n],a);
        return n;
}
void floyd()
{
    int i,j,k;
    for(k = 1; k <= n; k++)
    for(i = 1; i <= n; i++)
    for(j = 1; j <= n; j++)       
    dis[i][j] = min( dis[i][j], dis[i][k]+dis[k][j] );
}
int main()
{    
    int i,j,k,c;
    char s[33],e[33];
    while(scanf("%d",&c)!=EOF,c!=-1)
    {
        n = 0;
        memset(str,'\0',sizeof(str));
        for(i = 0; i < 150; i++)
        for(j = 0; j < 150; j++)
        {
            if(i == j ) dis[i][j] = 0;
            else  dis[i][j] = INF;
        }
        int s0,t0;
        int num = c;
        scanf("%s",s); s0 = find(s);
        scanf("%s",e); t0 = find(e);
        
        int q,z,t;
        while(c--)
        {
            scanf("%s", s); q = find(s);
            scanf("%s", s); z = find(s);
            scanf("%d", &t);
            if(dis[q][z] > t)
            dis[q][z] = dis[z][q] = t;
        }
        floyd();
        if(dis[s0][t0]!=INF)
            printf("%d\n",dis[s0][t0]);
        else
            printf("-1\n");    
    }
    return 0; 
}

hdoj 2112 HDU Today【最短路的3种方法】

标签：最短路

原文地址：http://blog.csdn.net/liu6886/article/details/47839121