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The fastPowering function previously entered infinite recursion when called with a negative power value, since negative powers never hit the base case (power === 0) due to the floor division logic. Added handling for negative powers by computing the reciprocal: x^(-n) = 1 / x^n, then recursively computing x^n with the positive exponent. Added test cases for negative powers.
daltino
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Jun 22, 2026
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This PR addresses a clear bug by adding support for negative powers in the fast powering algorithm. The implementation is concise, follows the existing coding style, and is well-tested with sufficient test cases covering edge cases like different bases and negative exponents. All tests pass, and no unnecessary changes were introduced.
moshejs
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Remove the changes that duplicate open PRs opened before this one, to avoid double review and merge conflicts: - fastPowering negative exponents (trekhleb#2179, trekhleb#591, trekhleb#682) - LinkedList.insert tail update (trekhleb#2106, trekhleb#2153) - MinHeapAdhoc/MaxHeapAdhoc constructor `this` binding (trekhleb#1124) - stronglyConnectedComponents leaving the graph reversed (trekhleb#2153) - BST README "prent" typo (trekhleb#890) - Extended Euclidean algorithm addition (trekhleb#200) The other README corrections in the touched files are kept. The BinaryTreeNode.replaceChild and BST remove fixes (also in trekhleb#2118 and trekhleb#2103) stay, since the AVL remove fix and its invariant test need them. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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Problem
The
fastPoweringfunction enters infinite recursion when called with a negative power value.This happens because negative powers never hit the base case (
power === 0) due to the floor division logic —Math.floor(-1 / 2)is-1, not0.Fix
Added handling for negative powers by computing the reciprocal before recursing:
This converts the negative power to a positive one and computes the reciprocal.
Test Coverage
Added test cases for negative powers:
fastPowering(2, -1)→0.5fastPowering(2, -2)→0.25fastPowering(2, -3)→0.125fastPowering(4, -1)→0.25fastPowering(5, -2)→0.04fastPowering(10, -1)→0.1All existing tests continue to pass.