An algorithmic challenge to filter and sort the most frequent words from a slice, prioritizing frequency and then lexicographical order.

main.go

package main

import (
	"fmt"
	"reflect"
	"sort"
)

// Challenge: Top K Frequent Words
//
// Objective:
// Given an array of strings `words` and an integer `k`, return the `k` most frequent strings.
//
// Sorting Rules:
// 1. Sort by frequency from highest to lowest.
// 2. If two words have the same frequency, sort them by lexicographical order (alphabetically).
//
// Example:
// Input: ["i", "love", "coding", "i", "love", "go"], k = 2
// Output: ["i", "love"]
// Explanation: "i" and "love" are the two most frequent words.
// Note: "i" comes before "love" due to higher frequency? No, both have 2. "i" comes before "love" alphabetically.

func TopKFrequent(words []string, k int) []string {
	// TODO: Implement the logic here
	
	return []string{}
}

func main() {
	// --- Test Case 1 ---
	input1 := []string{"i", "love", "golang", "i", "love", "coding"}
	k1 := 2
	expected1 := []string{"i", "love"} 
	// Both have count 2. 'i' comes before 'love' alphabetically.

	// --- Test Case 2 ---
	input2 := []string{"orange", "apple", "banana", "apple", "orange", "apple", "banana"}
	k2 := 3
	expected2 := []string{"apple", "banana", "orange"} 
	// apple: 3, banana: 2, orange: 2. (banana comes before orange alphabetically)

	fmt.Println("--- Running Tests ---")

	// Execution & Validation for Case 1
	result1 := TopKFrequent(input1, k1)
	if reflect.DeepEqual(result1, expected1) {
		fmt.Println("✅ Test 1 Passed")
	} else {
		fmt.Printf("❌ Test 1 Failed.\n   Expected: %v\n   Got:      %v\n", expected1, result1)
	}

	// Execution & Validation for Case 2
	result2 := TopKFrequent(input2, k2)
	if reflect.DeepEqual(result2, expected2) {
		fmt.Println("✅ Test 2 Passed")
	} else {
		fmt.Printf("❌ Test 2 Failed.\n   Expected: %v\n   Got:      %v\n", expected2, result2)
	}
}