[LeetCode] 多数元素【169】

问题: 给定一个大小为n的数组nums，返回其中的多数元素(多数元素是指在数组中出现次数大于n/2的元素)

你可以假设数组是非空的，并且给定的数组总是存在多数元素

示例1

输入: nums = [3,2,3]

输出: 3

示例2

输入: nums = [2,2,1,1,1,2,2]

输出: 2

Python3解题 

# 解法1
def majorityElement(nums):
   length = len(nums) / 2
   set_nums = set(nums)
   for i in set_nums:
       if nums.count(i) > length:
           return i

# 解法2
import collections
def majorityElement(nums):
    counts = collections.Counter(nums)
    return max(counts.keys(), key=counts.get)

majorityElement([3,2,3]) # 3
majorityElement([2,2,1,1,1,2,2]) # 2

涉及知识点:

[Python] set()函数https://blog.csdn.net/Hudas/article/details/122882024
[Python] count()方法https://blog.csdn.net/Hudas/article/details/122941544