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 646 with 11 pytest cases. Generate a practice environment with lcpy.
lcpy gen -n 646 # by problem number
lcpy gen -s maximum_length_of_pair_chain # by problem name
n pairs pairs where pairs[i] = [lefti, righti] and lefti < righti.
A pair p2 = [c, d] follows a pair p1 = [a, b] if b < c. A chain of pairs can be formed in this fashion.
Return the length longest chain which can be formed.
You do not need to use up all the given intervals. You can select pairs in any order.
Input: pairs = [[1,2],[2,3],[3,4]]
Output: 2
Explanation: The longest chain is [1,2] -> [3,4].
Input: pairs = [[1,2],[7,8],[4,5]]
Output: 3
Explanation: The longest chain is [1,2] -> [4,5] -> [7,8].
class Solution:
# Time: O(n log n)
# Space: O(n) for the sorted copy
def find_longest_chain(self, pairs: list[list[int]]) -> int:
count = 0
chain_end = float("-inf")
for left, right in sorted(pairs, key=lambda pair: pair[1]):
if left > chain_end:
count += 1
chain_end = right
return count
| Time | Space |
|---|---|
| O(n log n) | O(n) for the sorted copy |