Question

How to generate a random integer from a range [0, N] that is not in a unique integer list with Go

Answer 1

package main

import (
    "fmt"
    "math/rand"
    "time"
)

func randomExcluding(N int, excluded []int) int {
    if len(excluded) > N + 1 {
        return -1 // All numbers are excluded
    }

    rand.Seed(time.Now().UnixNano())

    for {
        num := rand.Intn(N + 1)
        if !contains(excluded, num) {
            return num
        }
    }
}

func contains(slice []int, value int) bool {
    for _, v := range slice {
        if v == value {
            return true
        }
    }
    
    return false
}

func main() {
    excluded := []int{2, 5, 7}
    N := 14

    result := randomExcluding(N, excluded)
    fmt.Println(result)
}



/*
run:

9

*/

 

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