819. Partition Array

Implement a partition function that splits an array into two groups based on a predicate function.

1. Basic Functionality

• Accept an array and a predicate function
• Return an array of two arrays: [truthy, falsy]
• First array contains elements where predicate returns truthy
• Second array contains elements where predicate returns falsy
• Preserve the original order within each group

Examples

partition([1, 2, 3, 4, 5], n => n % 2 === 0);
// Returns: [[2, 4], [1, 3, 5]]

partition(['apple', 'banana', 'cherry'], s => s.length > 5);
// Returns: [['banana', 'cherry'], ['apple']]