fix(matrix): use adjoint_matrix for 3x3 inverse computation#14838
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maitriupadhyay03-cell wants to merge 6 commits into
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fix(matrix): use adjoint_matrix for 3x3 inverse computation#14838maitriupadhyay03-cell wants to merge 6 commits into
maitriupadhyay03-cell wants to merge 6 commits into
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…gorithms#7854) The split() function in treap.py uses `<` comparison but the docstring states that the right subtree should contain values "greater or equal" to the split value. This fix changes `elif value < root.value:` to `elif value <= root.value:` so that equal values go to the right subtree as documented. Fixes TheAlgorithms#7854
The 3x3 inverse computation had a bug: it was using cofactor_matrix instead of adjoint_matrix when seeding inverse_matrix (line ~148). The adjoint is correctly computed as the transpose of the cofactor matrix, but then discarded. This fix uses adjoint_matrix as required by the formula: inverse = (1/det) * adjoint. Also updates the 3x3 doctest to assert the correct inverse values. Fixes TheAlgorithms#14813
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The inorder() function previously used print() to output values, which made its doctests thread-unsafe (pytest-run-parallel does not support doctests that use print). This fix: - Changes inorder() to return a comma-separated string instead of printing - Updates all interact_treap doctests to assert the returned string value - Adds a doctest to inorder() itself Fixes the CI failure: FAILED data_structures/binary_tree/treap.py::data_structures.binary_tree.treap.interact_treap
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Describe your change:
Fix a bug in
matrix/inverse_of_matrix.pywhere the 3x3 inverse computation returned the transpose of the correct inverse instead of the actual inverse.Root cause: The function correctly computed
adjoint_matrixas the transpose ofcofactor_matrix, but then initializedinverse_matrixfromcofactor_matrixinstead ofadjoint_matrix. This meantinverse_matrixwas seeded with the un-transposed cofactor data, producing a result equal to(1/det) * cofactor— which is the transpose of the true inverse.Fix: Seed
inverse_matrixfromadjoint_matrix(notcofactor_matrix), as required by the formula:A⁻¹ = (1/det(A)) * adj(A).Also updated: The 3x3 doctest which was asserting the previously wrong (transposed) values.
Fixes #14813
Checklist: