The challenge

Given an array of integers your solution should find the smallest integer.

For example:

  • Given [34, 15, 88, 2] your solution will return 2
  • Given [34, -345, -1, 100] your solution will return -345

You can assume, for the purpose of this challenge, that the supplied array will not be empty.

The solution in Golang

Option 1:

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package solution
func SmallestIntegerFinder(numbers []int) int {
  curr := numbers[0]
  for _, v := range numbers {
    if v<curr {
      curr = v
    }
  }
  return curr
}

Option 2:

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package solution
import "sort"
func SmallestIntegerFinder(numbers []int) int {
  sort.Ints(numbers)
  return numbers[0]
}

Option 3:

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package solution
func SmallestIntegerFinder(numbers []int) int {  
  return quickSort(numbers)[0]
}
func quickSort( input []int) []int{
  if len(input)==0 {
    return []int{}
  }
  index:=len(input)/2
  temp:=input[index]
  var lower []int
  var greater []int
  for i:= range input{
    if i==index {
      continue
    }
    if input[i] <= temp {
      lower = append(lower, input[i])
    } else {
      greater = append(greater, input[i])
    }
  }
  result:=append(quickSort(lower), temp)
  return append(result, quickSort(greater)...)
}

Test cases to validate our solution

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package solution_test
import (
  . "github.com/onsi/ginkgo"
  . "github.com/onsi/gomega"
  "math/rand"
  "sort"
  "time"
)
func _solution(numbers []int) int {
  sort.Ints(numbers)
  return numbers[0]
}
var _ = Describe("Test Example", func() {
  It("should work for sample tests", func() {
    Expect(Expect(SmallestIntegerFinder([]int{34, 15, 88, 2})).To(Equal(2)))
    Expect(Expect(SmallestIntegerFinder([]int{34, -345, -1, 100})).To(Equal(-345)))
  })
  rand.Seed(time.Now().UTC().UnixNano())
  min, max := -100, 100
  It("should work for random tests", func() {
    for i := 0; i < 500; i++ {
      arrLen := 10 + rand.Intn(100)
      var arrInts []int
      for j := 0; j < arrLen; j++ {
        arrInts = append(arrInts, rand.Intn(max - min + 1) + min)
      }
      ts := SmallestIntegerFinder(arrInts)
      r := _solution(arrInts)
      Expect(ts).To(Equal(r))
    }
  })
})