Majority Element
题目详情:
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.
Credits:
Special thanks to @ts for adding this problem and creating all test cases.
解题方法:
这是一道非常经典的算法题,寻找众数。首先初始化一个result,和一个count都为0,分别用来存放结果和计数。当count为0时,result为nums[i],count+1,否则当result==nums[i]时count+1,result != nums[i]时,count-1,result即为想要的结果。
详细代码:
class Solution {
public:
int majorityElement(vector<int>& nums) {
int result = 0;
int count = 0;
for (int i = 0; i < nums.size(); i++) {
if(count == 0) {
result = nums[i];
count = 1;
}
else {
if(result == nums[i])
count++;
else
count--;
}
}
return result;
}
};
复杂度分析:
时间复杂度为O(n),仅遍历了一次数组。