containsDuplicate.go

package main

import "fmt"

func main() {
	fmt.Println(containsDuplicate([]int{1, 2, 3, 4}))
}

func containsDuplicate(nums []int) bool {
	ret := make(map[int]bool, len(nums))
	for j := 0; j < len(nums); j++ {
		if ret[nums[j]] {
			return true
		} else {
			ret[nums[j]] = true
		}
	}
	return false
}