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LESSON 195 OF 414 · NESTED LOOPS

Top K Brands V6 - Tie-Break by Review Count in Kotlin

Practice

Rank the top k brands by rating, breaking ties with the review count. This builds on v4's repeated search (not on v5: there is no filtering here); only the comparison gets a second criterion.

You start with:

        val brands = arrayOf("TechPro", "MegaCorp", "NeoByte", "Quantum", "Zenith")
        val ratings = intArrayOf(4, 5, 5, 3, 4)
        val reviews = intArrayOf(200, 150, 500, 100, 300)
        val k = 3

Build:

1. NeoByte (5, 500)
2. MegaCorp (5, 150)
3. Zenith (4, 300)

Rules:

  • Rating decides first: the higher rating wins.
  • If two brands have the same rating, the one with more reviews wins.
  • If rating and reviews are both equal, the one listed first wins (the test data has no such pair, but your code must follow the rule).
  • k is never larger than the number of brands.
  • Each line is "rank. Brand (rating, reviews)", starting at rank 1.
  • Print the lines, one per line, with println(...).

Start from v4: the same val used = BooleanArray(ratings.size) and val lines = mutableListOf<String>(), the same two loops. Only the comparison inside the inner loop changes.

Use a chain (if / else if / else if): no candidate yet, take this one; else a higher rating, take this one; else the same rating and more reviews, take this one.

        val brands = arrayOf("TechPro", "MegaCorp", "NeoByte", "Quantum", "Zenith")
        val ratings = intArrayOf(4, 5, 5, 3, 4)
        val reviews = intArrayOf(200, 150, 500, 100, 300)
        val k = 3

        val used = BooleanArray(ratings.size)
        val lines = mutableListOf<String>()
        for (rank in 1..k) {
            var bestIndex = -1
            for (i in ratings.indices) {
                if (!used[i]) {
                    if (bestIndex == -1) {
                        bestIndex = i
                    }
                    else if (ratings[i] > ratings[bestIndex]) {
                        bestIndex = i
                    }
                    else if (ratings[i] == ratings[bestIndex] && reviews[i] > reviews[bestIndex]) {
                        bestIndex = i
                    }
                }
            }
            used[bestIndex] = true
            lines.add("$rank. ${brands[bestIndex]} (${ratings[bestIndex]}, ${reviews[bestIndex]})")
        }
        println(lines.joinToString("\n"))

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    Top K Brands V6 in Kotlin

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