169. Majority Element

最新推荐文章于 2025-09-09 19:16:33 发布

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最新推荐文章于 2025-09-09 19:16:33 发布

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文章标签： c/c++

原文链接：http://www.cnblogs.com/ruruozhenhao/p/10331321.html

本文详细解析了在数组中寻找出现次数超过一半的多数元素的算法。通过使用HashMap的方法，展示了如何遍历数组并计数每个元素的出现次数，进而找到满足条件的多数元素。附带的代码示例清晰地演示了这一过程。

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.

You may assume that the array is non-empty and the majority element always exist in the array.

Example 1:

Input: [3,2,3]
Output: 3

Example 2:

Input: [2,2,1,1,1,2,2]
Output: 2

Approach #1: HashMap. [C++]

class Solution {
public:
    int majorityElement(vector<int>& nums) {
        map<int, int> mp;
        int n = nums.size();
        int ans = 0;
        for (int num: nums) 
            mp[num]++;
        map<int, int>::iterator it;
        it = mp.begin();
        while (it != mp.end()) {
            if (it->second > n/2)
                ans = it->first;
            it++;
        }
        return ans;
    }
};

转载于:https://www.cnblogs.com/ruruozhenhao/p/10331321.html