package main
import "fmt"
func main() {
intarr := []int{1, 3, 4, 2, 2}
duplicate := findDuplicate(intarr)
fmt.Println(duplicate)
}
func findDuplicate(nums []int) int {
numse := make(map[int]int)
for i := range nums {
if _, ok := numse[nums[i]]; ok {
return nums[i]
}
numse[nums[i]] = i
}
return 0
}