Query Kth Smallest Trimmed Number

You are given a 0-indexed array of strings nums, where each string is of equal length and consists of only digits.

You are also given a 0-indexed 2D integer array queries where queries[i] = [ki, trimi]. For each queries[i], you need to:

  • Trim each number in nums to its rightmost trimi digits.
  • Determine the index of the kith smallest trimmed number in nums. If two trimmed numbers are equal, the number with the lower index is considered to be smaller.
  • Reset each number in nums to its original length.

Return an array answer of the same length as queries, where answer[i] is the answer to the ith query.

Note:

  • To trim to the rightmost x digits means to keep removing the leftmost digit, until only x digits remain.
  • Strings in nums may contain leading zeros.

 

Example 1:

Input: nums = ["102","473","251","814"], queries = [[1,1],[2,3],[4,2],[1,2]]
Output: [2,2,1,0]
Explanation:
1. After trimming to the last digit, nums = ["2","3","1","4"]. The smallest number is 1 at index 2.
2. Trimmed to the last 3 digits, nums is unchanged. The 2nd smallest number is 251 at index 2.
3. Trimmed to the last 2 digits, nums = ["02","73","51","14"]. The 4th smallest number is 73.
4. Trimmed to the last 2 digits, the smallest number is 2 at index 0.
   Note that the trimmed number "02" is evaluated as 2.

Example 2:

Input: nums = ["24","37","96","04"], queries = [[2,1],[2,2]]
Output: [3,0]
Explanation:
1. Trimmed to the last digit, nums = ["4","7","6","4"]. The 2nd smallest number is 4 at index 3.
   There are two occurrences of 4, but the one at index 0 is considered smaller than the one at index 3.
2. Trimmed to the last 2 digits, nums is unchanged. The 2nd smallest number is 24.

 

Constraints:

  • 1 <= nums.length <= 100
  • 1 <= nums[i].length <= 100
  • nums[i] consists of only digits.
  • All nums[i].length are equal.
  • 1 <= queries.length <= 100
  • queries[i].length == 2
  • 1 <= ki <= nums.length
  • 1 <= trimi <= nums[i].length
SOLUTION:
class Solution:
    def smallestTrimmedNumbers(self, nums: List[str], queries: List[List[int]]) -> List[int]:
        n = len(nums)
        trims = [[] for _ in range(101)]
        l = max(len(el) for el in nums)
        for i in range(1, l + 1):
            for j in range(n):
                trims[i].append((int(nums[j][-i:]), j))
            trims[i].sort()
        res = []
        for k, trim in queries:
            res.append(trims[trim][k - 1][1])
        return res

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