Djikstra算法

时间:2015-06-05 18:13:08

标签: c++ algorithm data-structures dijkstra shortest-path

我有这个函数来计算使用Dijkstra的最短路径但是代码在某些测试用例中给出了一些错误。我可以找到代码中的逻辑错误。任何帮助将不胜感激。

 int minDistance(int *dist, bool *includ,int no_of_vertices);
int* shortestDist(int** graph, int src, int no_of_vertices)
{
     int u,a=no_of_vertices;
     int min = MAXval;int  min_index;
     int* dist= new int[no_of_vertices];     

     bool *includ = new bool[no_of_vertices]; 

     for (int i = 0; i < a ; i++)
       { dist[i] = MAXval;
        includ[i] = false;}


     dist[src] = 0;


     for (int count = 0; count < a-1; count++)
     {


      int u = minDistance(dist, includ,a);

       includ[u] = true;


       for (int v = 0; v < a; v++)


         if (!includ[v] && graph[u][v]  && ((dist[u]+graph[u][v]) < dist[v]))
            dist[v] = dist[u] + graph[u][v];

    }

     return dist;

}
int minDistance(int *dist, bool *includ,int no_of_vertices)
{            


   int min = MAXval;int min_index;

   for (int v = 0; v < no_of_vertices; v++)
   {
     if (includ[v] == false && dist[v] <= min)
         min = dist[v]; min_index = v;
 }
   return min_index;
}

测试用例:

3
2
0 4 0
4 0 1
0 1 0

预期o / p

0:5
1:1
2:0

实际o / p

0:1000
1:1
2:0

1 个答案:

答案 0 :(得分:3)

minDistance()

 if (includ[v] == false && dist[v] <= min)
     min = dist[v]; min_index = v;

你错过了{ }。无论条件是真还是假,都会执行min_index = v;