leetcode1287. Element Appearing More Than 25% In Sorted Array

Posted 2021-03-23 seyjs

题目如下：

Given an integer array sorted in non-decreasing order, there is exactly one integer in the array that occurs more than 25% of the time.

Return that integer.

Example 1:

Input: arr = [1,2,2,6,6,6,6,7,10]
Output: 6

Constraints:

• 1 <= arr.length <= 10^4
• 0 <= arr[i] <= 10^5

解题思路：最直接的方法是统计每个元素出现的次数。

代码如下：

class Solution(object):
    def findSpecialInteger(self, arr):
        """
        :type arr: List[int]
        :rtype: int
        """
        dic = {}
        res = 0
        for i in arr:
            dic[i] = dic.setdefault(i,0) + 1
            if dic[i] > len(arr)/4:
                res = i
                break
        return res