The Runtime Theory
mediumLeetCode#minimum-spanning-tree#prim

Min Cost to Connect All Points

Connect every point with minimum total Manhattan-distance edge cost.

The Runtime Theory Team25 min read
Solve it

Solving happens on the judge — come back and mark it done

Sample cases

inpoints=[[0,0],[2,2],[3,10],[5,2],[7,0]]

out20

inpoints=[[3,12],[-2,5],[-4,1]]

out18

inpoints=[[1,1],[1,1]]

out0

Connect every point with minimum total Manhattan-distance edge cost.

A good solution should

  • State the invariant or decision rule that makes the approach correct.
  • Explain time and space costs in terms of input size and required output.
  • Handle empty, minimal, duplicate, and boundary-shaped inputs.

Reasoning prompt

Model points as a complete weighted graph, but avoid materializing every edge if using Prim’s algorithm.

Use the linked judge for the canonical challenge. The examples above are compact TRT checks; create additional tests around the boundary most likely to break your invariant.

More practice in this topic

One dispatch a week

The trace behind each problem, the tradeoff that explains it, and one technical dispatch per week — no noise.

One technical dispatch per week. No noise.

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