The Runtime Theory
easyLeetCode#recursion#tree-comparison

Same Tree

Determine whether two trees have identical shape and values at corresponding positions.

The Runtime Theory Team25 min read
Solve it

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

Sample cases

inp=[1,2,3], q=[1,2,3]

outtrue

inp=[1,2], q=[1,null,2]

outfalse

inp=[1,2,1], q=[1,1,2]

outfalse

Determine whether two trees have identical shape and values at corresponding positions.

A good solution should

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

Reasoning prompt

Compare null structure as well as values. A traversal value sequence without shape markers can be ambiguous.

Use the linked judge for the canonical problem. The examples above are compact TRT checks; write additional cases before submitting, especially for the boundary that tends to break your chosen invariant.

More practice in this topic

easy · treesBalanced Binary Treemedium · treesBinary Tree Level Order Traversalmedium · treesBinary Tree Right Side View

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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