MSTree PrimMST(Graph g)
{
   MST = empty graph (nV(g))
   usedV = {0};  unusedE = edges(g)
   while (size(usedV) < nV(g)) {
      find (edge e in unusedE) satisfying {
         e = (s,t,w), s ∈ usedV, t ∉ usedV,
         w is min weight of all such edges
      }
      add e = (s,t,w) to MST
      usedV += t;  unusedE -= e
   }
   return MST
}