Issue
I am learning golang, and I am trying to work through writing bubblesort and working with pointers.
package main
import (
"fmt"
"math/rand"
)
func main() {
testTwo := make([]int, 10)
for i := 0; i <= len(testTwo)-1; i++ {
fmt.Print("\n")
testTwo[i] = rand.Intn(10)
}
for i := 0; i <= len(testTwo)-1; i++ {
for j := i + 1; j <= len(testTwo)-1; j++ {
testTwo[i], testTwo[i+1] = swap(testTwo[i], testTwo[i+1])
}
}
}
/*
Swaps the pointers of two adjacent elements in an array
*/
func swap(valOne, valTwo int) (int, int) {
valAddress := &valOne
valAddressTwo := &valTwo
if valOne <= valTwo {
temp_address := *valAddressTwo
*valAddressTwo = valOne
*valAddress = temp_address
} else {
temp_address := *valAddress
*valAddress = valTwo
*valAddressTwo = temp_address
}
return valOne, valTwo
}
This is an example of what is being done so far. The input slice might be
[4 1 2 9 8 4 1 5 7 6]. But it stops short of sorting everything.[1 4 9 2 4 8 5 1 6 7]. Is there another condition I should add or is there something wrong with how I am using the pointers in the swap function?
Solution
package main
import (
"fmt"
"math/rand"
)
func main() {
testTwo := make([]int, 10)
for i := 0; i <= len(testTwo)-1; i++ {
fmt.Print("\n")
testTwo[i] = rand.Intn(10)
}
for i := 0; i <= len(testTwo)-1; i++ {
for j := i + 1; j <= len(testTwo)-1; j++ {
if testTwo[i] > testTwo[j] {
// here we swap pointers
testTwo[i], testTwo[j] = swap(testTwo[i], testTwo[j])
}
}
}
fmt.Print(testTwo)
}
/*
GO always sends arguments by value. Pointers cannot be swapped here, unless we use *int
*/
func swap(valOne, valTwo int) (int, int) {
if valOne <= valTwo {
return valOne, valTwo
} else {
return valTwo, valOne
}
}
Answered By – Dmitry Harnitski
Answer Checked By – Willingham (GoLangFix Volunteer)