Question

How to write a recursive function to generate all permutations of a string in Go

Answer 1

package main

import (
    "fmt"
)

func swap(arr []rune, i, j int) {
    arr[i], arr[j] = arr[j], arr[i]
}

func generatePermutation(arr []rune, l, r int) {
    if l == r {
        fmt.Println(string(arr))
    } else {
        for i := l; i <= r; i++ {
            swap(arr, l, i)
            generatePermutation(arr, l + 1, r)
            swap(arr, l, i) // backtrack
        }
    }
}

func main() {
    s := "ABC"
    
    runes := []rune(s)
    
    generatePermutation(runes, 0, len(runes)-1)
}

 

/*
run:

0100100000101000
First set bit at index: 3
All the set bits indexes:
3 5 11 14 

*/

 

70+ SQL courses for beginners and professionals