The challenge

Complete the method which returns the number which is most frequent in the given input array. If there is a tie for the most frequent number, return the largest number among them.

Note: no empty arrays will be given.

Examples 

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[12, 10, 8, 12, 7, 6, 4, 10, 12]              -->  12
[12, 10, 8, 12, 7, 6, 4, 10, 12, 10]          -->  12
[12, 10, 8, 8, 3, 3, 3, 3, 2, 4, 10, 12, 10]  -->   3

The solution in Golang

Option 1:

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package solution
func HighestRank(nums []int) int {
  mii, maxK, maxV := map[int]int{}, 0, 0
  for _, v := range nums {
    mii[v]++
    if mii[v] > maxV || (mii[v] == maxV && v > maxK) {
      maxK = v
      maxV = mii[v]
    }
  }
  return maxK
}

Option 2:

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package solution
func HighestRank(nums []int) int {
  fs := make(map[int]int)
  for _, n := range nums {
    fs[n]++
  }
  maxf, maxfn := 0, 0
  for n, f := range fs {
    if f >= maxf && (f > maxf || n > maxfn) {
      maxf, maxfn = f, n
    }
  }
  return maxfn
}

Option 3:

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package solution
func HighestRank(nums []int) int {
  occurrences := make(map[int]int)
  var max, val int
  for _, value := range nums {
    occurrences[value]++
  }
  max, val = occurrences[nums[0]], nums[0]
  for value, times := range occurrences {
    if times > max {
      val = value
      max = times
    } else if times == max {
      if value > val {
        val = value
      }
    }
  }
  return val
}

Test cases to validate our solution

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package solution_test
import (
  . "github.com/onsi/ginkgo"
  . "github.com/onsi/gomega"
)
var _ = Describe("Tests", func() {
    Describe("Sample tests", func() {
        It("Sample test 1: 12, 10, 8, 12, 7, 6, 4, 10, 12", func() {
            Expect(HighestRank([]int{12, 10, 8, 12, 7, 6, 4, 10, 12 })).To(Equal(12))
        })
    })
})