Documentation Index
Fetch the complete documentation index at: /llms.txt
Use this file to discover all available pages before exploring further.
Tested Python solution for LeetCode 248 with 16 pytest cases. Generate a practice environment with lcpy.
lcpy gen -n 248 # by problem number
lcpy gen -s strobogrammatic_number_iii # by problem name
low and high where low <= high, return the number of strobogrammatic numbers in the range [low, high].
A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).
Input: low = "50", high = "100"
Output: 3
Input: low = "0", high = "0"
Output: 1
1 <= low.length, high.length <= 15low and high consist of only digits.low <= highlow and high do not contain any leading zeros except for zero itself.class Solution:
# Time: O(2^n * n)
# Space: O(2^n)
def strobogrammatic_in_range(self, low: str, high: str) -> int:
def build(length: int, outermost: bool) -> list[str]:
if length == 0:
return [""]
if length == 1:
return ["0", "1", "8"]
results: list[str] = []
for middle in build(length - 2, False):
for left, right in ("11", "88", "69", "96"):
results.append(left + middle + right)
if not outermost:
results.append("0" + middle + "0")
return results
count = 0
for length in range(len(low), len(high) + 1):
for candidate in build(length, True):
if int(low) <= int(candidate) <= int(high):
count += 1
return count
| Time | Space |
|---|---|
| O(2^n * n) | O(2^n) |