Dijkstra's Algorithm - Setup

Before the main loop, you need to initialize two things:

$1.$ Create a distance array dist[N] initialized to infinity (a large number like $10^{18}$). This tracks the shortest known distance to each node.

$2.$ Set dist[start] = 0. The distance from the start to itself is zero.

$3.$ Create a priority queue (min-heap) and push (0, start). The pair represents (distance, node).

dist := array of INF, size n
dist[start] := 0
pq := min-heap with (0, start)

Now you are ready for the main Dijkstra loop: repeatedly extract the minimum and relax neighbors.