backtracking: add unique permutation algorithm with test cases (#7078)

* Add unique permutation algorithm and test cases

* Fix: add braces for checkstyle

* Apply clang-format

shreeya-g10 committed 6mo ago

3519e396af269683a42796ef653b37abdcd7d791

Parent: 1c97ad8

Committed by GitHub <noreply@github.com> on 11/19/2025, 4:20:46 PM