Leetcode 646. Maximum Length of Pair Chain

class Solution:
    def findLongestChain(self, pairs: List[List[int]]) -> int:
        pairs.sort(key=lambda x: x[1])
        result = []
        n = len(pairs)
        result.append(pairs[0])
        for i in range(1, n):
            if pairs[i][0] > result[-1][1]:
                result.append(pairs[i])
        return len(result)

class Solution:
    def findLongestChain(self, pairs: List[List[int]]) -> int:
        pairs.sort(key=lambda x: x[1])
        n = len(pairs)
        pre = pairs[0]
        count = 1
        for i in range(1, n):
            if pairs[i][0] > pre[1]:
                pre = pairs[i]
                count += 1
        return count