examples: add new graph algorithms, make some minor corrections to the programs in examples/graphs (#14562)

examples/graphs/bellman-ford.v

@@ -8,7 +8,7 @@ https://www.geeksforgeeks.org/bellman-ford-algorithm-dp-23/
 For Portugese reference
 http://rascunhointeligente.blogspot.com/2010/10/o-algoritmo-de-bellman-ford-um.html
 
-By CCS
+code by CCS
 */
 
 const large = 999999 // almost inifinity
@@ -159,5 +159,3 @@ fn main() {
 	}
 	println('\n BYE -- OK')
 }
-
-//=================================================

examples/graphs/dijkstra.v

@@ -237,5 +237,3 @@ fn main() {
 
 	println('\n BYE -- OK')
 }
-
-//********************************************************************

examples/graphs/minimal_spann_tree_prim.v

@@ -8,8 +8,9 @@ by CCS
 PS: all the pre-requisites of Dijkstra are considered
 
 $ v run file_name.v
+
 Creating a executable
-$ v  run file_name.v  -o an_executable.EXE
+$ v -o an_executable.EXE run file_name.v
 $ ./an_executable.EXE
 
 Code based from : Data Structures and Algorithms Made Easy: Data Structures and Algorithmic Puzzles, Fifth Edition (English Edition)
@@ -45,9 +46,7 @@ fn push_pq<T>(mut prior_queue []T, data int, priority int) {
 		temp << prior_queue[i]
 		i++
 	}
-	prior_queue = temp.clone()
-	// I am not sure if it the right way
-	// IS IT THE RIGHT WAY?
+	prior_queue = temp.clone() // I am not sure if it the right way
 }
 
 // Change the priority of a value/node ... exist a value, change its priority
@@ -193,9 +192,6 @@ fn main() {
     |  /     \  |
     (3)-------(4)
          9
-	*/
-
-	/*
 	Let us create following weighted graph
  From https://www.geeksforgeeks.org/kruskals-minimum-spanning-tree-algorithm-greedy-algo-2/?ref=lbp
                    10
@@ -226,5 +222,3 @@ fn main() {
 	}
 	println('\n BYE -- OK')
 }
-
-//********************************************************************