Problem #24

Problem link
Solution:

package main

var used []bool

func main() {
    used = make([]bool, 10)
    for i := range used {
        used[i] = false
    }
    remaining := 999999
    perm := 1
    index := 0
    for i := 9; i > 0; i-- {
        perm = 1
        for j := i; j > 0; j-- {
            perm *= j
        }
        index = remaining / perm
        remaining = remaining % perm
        j := 0
        for j = 0; j < index || used[j]; j++ {
            if used[j] {
                index++
            }
        }
        used[j] = true
        print(j)
    }
    println(remaining)
}

Result: 2783915460
Time: 0m0.003s