I got this question in an interview recently. I was given a bunch of points (for eg.- Start(88, 81), Dest(85,80), P1(19, 22), P2(31, 15), P3(27, 29), P4(30, 10), P5(20, 26), P6(5, 14)) on a 2D plane and any two of them were Source and Destination. I was asked to calculate the least cost to travel all the points starting from the source and ending on Destination point. The cost to travel between any two points is |x1 - x2| + |y1 - y2|.
So, what I thought of doing was construct a cost matrix and apply Dijkstra since I thought constructing the shortest path tree must be the solution.
But I couldn't think on how to construct this cost matrix. What is the best approach for this?