easy solution
IntuitionApproachComplexity
Time complexity:

Space complexity:
Code
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```javascript []
/**
 * @param {Array} arr
 * @param {number} depth
 * @return {Array}
 */
var flat = function (arr, n) {
    const res = [];

    function helper(arr,depth) {
        for(const val of arr) {
            if(typeof(val) === 'object' && depth < n) {
                helper(val,depth + 1);
            } else {
                res.push(val);
            }
        }
        return res;
    }
    return helper(arr,0);
};
```
['JavaScript']