6kyu¶ 6kyu Find Int That Appears Odd Number of Times Approach 1 (search and count) Approach 2 Bitwise XOR TypeScript Unit Tests Solution 1 (single function, approach 1) Solution 2 (helper functions, approach 1) Solution 3 (bitwise XOR) Scheme The Test Suit v1 single function v2 smaller, composable functions Unit Tests for the Helper Functions Implementation using the composed functions v3 car cdr Unit Tests for the Helper Functions Implementation using car, cdr and null? Which Are In Approach 1 JavaScript The Test Suite Solution 1 TypeScript The Test Suite Solution 1 Scheme The Test Suite Solution 1 Friend or Foe Approach 1 JavaScript Unit Tests Solution 1 TypeScript Unit Tests Solution 1 Scheme Unit Tests