Majority Element II
Total Accepted:
3172 Total Submissions:
14746
Given an integer array of size n, find all elements that appear more than? n/3 ? times. The algorithm should run in linear time and in O(1) space.
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[思路]
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观察可知,数组中至多可能会有2个出现次数超过 ? n/3 ? 的众数
记变量n1, n2为候选众数; c1, c2为它们对应的出现次数
遍历数组,记当前数字为num
若num与n1或n2相同,则将其对应的出现次数加1
否则,若c1或c2为0,则将其置为1,对应的候选众数置为num
否则,将c1与c2分别减1
最后,再统计一次候选众数在数组中出现的次数,若满足要求,则返回之。
[CODE]
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public class Solution {
public List
majorityElement(int[] nums) {
// 1, 2
List
res = new ArrayList<>(); if(nums==null || nums.length==0) return res; if(nums.length==1) { res.add(nums[0]); return res; } int m1 = nums[0]; int m2 = 0; int c1 = 1; int c2 = 0; for(int i=1; i
nums.length/3) res.add(m1); if(c2>nums.length/3) res.add(m2); return res; } }
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