# 1346. Check If N and Its Double Exist

🟩 Easy

## Solution

My Solution

```go
func checkIfExist(arr []int) bool {
    m := make(map[int]bool, len(arr))

    for _, num := range arr {
        if _, ok := m[num*2]; ok || (num%2 == 0 && m[num/2]) {
            return true
        }
        m[num] = true
    }

    return false
}
```

![result](https://600345290-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FrSK2xH3txU3tYyDsT8mQ%2Fuploads%2Fgit-blob-6d02b13566e48e011ebd62daf87bd17e6dd4aec4%2F1346.png?alt=media)

Leetcode: [link](https://leetcode.com/problems/check-if-n-and-its-double-exist/description/)