Each edge needs to be considered once ⇒ O(E).

Outer loop has O(V) iterations.

Implementing "find s∈vSet with minimum dist[s]"

1. try all s∈vSet ⇒ cost = O(V) ⇒ overall cost = O(E + V²) = O(V²)
2. using a PQueue to implement extracting minimum
   • can improve overall cost to O(E + V·log V)   (for best-known implementation)