1682. Level Totals of a Nest
A rental company stores its equipment catalogue as a nest of boxes: nestedList holds integers (stock counts) and boxes, and every box can hold more integers and more boxes. Integers that sit directly in nestedList are at depth 1, integers inside a box of nestedList are at depth 2, and so on.
Return an integer array totals where totals[d-1] is the sum of all integers at depth d, for every d from 1 to D, where D is the deepest depth that contains at least one integer. A depth between 1 and D that has no integers reports 0. If there are no integers at all, return an empty array. Aim for O(n) time and O(depth) extra space, where n counts all integers and boxes.
Example 1
- Input:
- nestedList = [1,[4,[6]]]
- Output:
- [1,4,6]
- Explanation:
The 1 is at depth 1, the 4 at depth 2 and the 6 at depth 3, so the totals are 1, 4 and 6.
Example 2
- Input:
- nestedList = [[1,1],2,[1,1]]
- Output:
- [2,4]
- Explanation:
Only the 2 is at depth 1, while the four 1s are at depth 2, giving [2, 4].
Example 3
- Input:
- nestedList = [[[5]],3]
- Output:
- [3,0,5]
- Explanation:
Depth 1 holds 3, depth 2 holds no integers so it reports 0, and depth 3 holds 5.
Constraints
At most 1000 integers and lists in total; nesting depth ≤ 50; -104 ≤ value ≤ 104
How this problem is judged
- Answers
- Your answer must match exactly. Numbers compare by value, so 2 and 2.0 are equal.
Expected complexity
- Time
- O(n)
- Space
- O(depth)