algorithm(leetcode) Contains Duplicate

containsDuplicate.go

package main

import "fmt"

func main() {

    fmt.Println(containsDuplicate([]int{1, 2, 3, 1}))                   //output true
    fmt.Println(containsDuplicate([]int{1, 2, 3, 4}))                   //output false
    fmt.Println(containsDuplicate([]int{1, 1, 1, 3, 3, 4, 3, 2, 4, 2})) //output true
}

func containsDuplicate(nums []int) bool {

    answer := false

    for i := 0; i < len(nums); i++ {
        duplicateCount := indexOf(nums[i], nums)

        if duplicateCount > 1 {
            answer = true
            break
        }
    }

    return answer
}

func indexOf(element int, data []int) int {
    count := 0
    for _, v := range data {
        if element == v {
            count++
        }
    }
    return count
}