added program in C

[vinay72]

I have added Program in C with implementing Dijkstra's Algorithm in the program. #51

[realwoopee]

And please add some tests. They're required in CONTRIBUTING.md

[realwoopee]

We need an algorithm description. Please check CONTRIBUTING.md

[vinay72]

Dijkstra’s Algorithm

1. Create cost matrix C[ ][ ] from adjacency matrix adj[ ][ ]. C[i][j] is the cost of going from vertex i to vertex j. If there is no edge between vertices i and j then C[i][j] is infinity.

2. Array visited[ ] is initialized to zero.
   for(i=0;i<n;i++)
   visited[i]=0;

3. If the vertex 0 is the source vertex then visited[0] is marked as 1.

4. Create the distance matrix, by storing the cost of vertices from vertex no. 0 to n-1 from the source vertex 0.
   for(i=1;i<n;i++)
   distance[i]=cost[0][i];
   Initially, distance of source vertex is taken as 0. i.e. distance[0]=0;

5. for(i=1;i<n;i++)
   – Choose a vertex w, such that distance[w] is minimum and visited[w] is 0. Mark visited[w] as 1.
   – Recalculate the shortest distance of remaining vertices from the source.
   – Only, the vertices not marked as 1 in array visited[ ] should be considered for recalculation of distance. i.e. for each vertex v
   if(visited[v]==0)
   distance[v]=min(distance[v],
   distance[w]+cost[w][v])
   Time Complexity
   The program contains two nested loops each of which has a complexity of O(n). n is number of vertices. So the complexity of algorithm is O(n2).

[realwoopee]

Sorry, I've mistyped the word "need". We don't need an algorithm description.

[realwoopee]

Please move your implementation file into the correct folder. Check CONTRIBUTING.md