Merge Three Sorted Arrays

Implement a function to merge three sorted integer arrays into a single sorted integer array. The output should consist of all integers from the three input arrays with no duplicates. Function signature mergeThreeArrays(arr1: List[int], arr2: List[int], arr3: List[int]) -> List[int]. Input: arr1: First sorted integer array. arr2: Second sorted integer array. arr3: Third sorted integer array. Output: Return a merged sorted integer array without duplicates. Example: Input: arr1 = [-1, -1, 0, 1], arr2 = [-2, 3, 5], arr3 = [-1, 0, 5] Output: [-2, -1, 0, 1, 3, 5] Example Input ([-1,0,1], [2,3], [-3,0,2,4])