HDU 1596 最短路变形

这道题怎么都是TLE，报警了，先放在这

http://acm.hdu.edu.cn/showproblem.php?pid=1596

#include <iostream>
#include <iomanip>
using namespace std;

#define MAXVEX 1001

double matrix[MAXVEX][MAXVEX];
double D[MAXVEX];

int n;

void Dijkstral(int v0)
{
          int v,w,k=1;
          double max;
          int final[MAXVEX];

          for(int i = 1;i<=n;i++)
          {
                    D[i] = matrix[v0][i];
                    final[i] = 0;
          }

          final[v0] = 1;

          for(v=1;v<=n;v++)
          {
                    max = -1;
                    for(w=1;w<=n;w++)
                    {
                              if(D[w]>max && !final[w])
                              {
                                       max = D[w];
                                       k = w;
                              }
                    }

                    final[k] = 1;

                    for(w=1;w<=n;w++)
                    {
                              if(max*matrix[k][w]>D[w] && !final[w])
                              {
                                        D[w]=max*matrix[v][w];
                              }
                    }
          }

}


int main()
{
          while(cin>>n)
          {
                    for(int i = 1;i<=n;i++)
                    {
                              for(int j = 1;j<=n;j++)
                                        cin>>matrix[i][j];
                    }

                    int m;
                    cin>>m;
                    while(m--)
                    {
                              int a,b;
                              cin>>a>>b;

                              Dijkstral(a);

                              if(D[b])
                                        cout<<fixed<<setprecision(3)<<D[b]<<endl;
                              else
                                        cout<<"What a pity!
";
                    }
          }
          return 0;
}

ac了，1482MS

#include <cstdio>
using namespace std;
const int L = 1010;
const int INF = 1<<27;

double map[L][L];
int vis[L];
double dis[L];

int n,m;

void Dijkstra(int s)
{
          int i,j,k;
          double max;
          for(i = 1;i<=n;i++)
          {
                    dis[i] = map[s][i];
                    vis[i] = 0;
          }

          vis[s] = 1;
          dis[s] = 0;

          for(i = 1;i<=n;i++)
          {
                    max = 0;
                    for(j = 1;j<=n;j++)
                    {
                              if(dis[j]>max && !vis[j])
                              {
                                        k = j;
                                        max = dis[j];
                              }
                    }

                    vis[k] = 1;

                    for(j = 1;j<=n;j++)
                    {
                              if(dis[j] < max*map[k][j] && !vis[j])
                              {
                                        dis[j] = max*map[k][j];
                              }
                    }
          }
}

void init()
{
          int i,j;
          for(i = 1;i<=n;i++)
          {

                    for(j = 1;j<=n;j++)
                    {
                              scanf("%lf",&map[i][j]);
                    }
          }
}


int main()
{
          while(scanf("%d",&n)!=EOF)
          {
                    int r,t;

                    init();

                    scanf("%d",&r);
                    while(r--)
                    {
                              int a,b;
                              scanf("%d%d",&a,&b);
                              Dijkstra(a);
                              if(dis[b])
                                        printf("%.3lf
",dis[b]);
                              else
                                        printf("What a pity!
");
                    }

          }

          return 0;
}