Majority Element 和 Majority Element II LeetCode Java__Java

Majority Element Total Accepted: 44517 Total Submissions: 127008 My Submissions Question Solution
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.

這道題，可以使用O（1）空間和O（n）時間複雜度實現，程式如下：

    public int majorityElement(int[] nums) {        int count =1;        int major=nums[0];        for(int i=1;i<nums.length;i++){            if(nums[i]==major){                count++;            }else if(count==0){                count++;                major=nums[i];            }else{                count--;            }        }        return major;    }

Majority Element II

Majority Element II Total Accepted: 302 Total Submissions: 1356 My Submissions Question Solution
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.

這道題目的思路和上一類似，程式如下：

    public List<Integer> majorityElement(int[] nums) {        List<Integer> rst=new ArrayList<Integer>();        int rst1=0,rst2=0;        int count1=0,count2=0;        int index=0;        int len=nums.length;        while(index<len){            int cur=nums[index];            if(count1!=0&&cur==rst1){                count1+=1;            }else if(count2!=0&&cur==rst2){                count2+=1;            }else if(count1==0){                rst1=cur;                count1+=1;            }else if(count2==0){                rst2=cur;                count2+=1;            }else {                count1--;                count2--;            }            index++;        }        count1=0;        count2=0;        for(int i=0;i<len;i++){            if(nums[i]==rst1){                count1++;            }else if(nums[i]==rst2){                count2++;            }        }        if(count1>len/3){            rst.add(rst1);        }        if(count2>len/3){            rst.add(rst2);        }        return rst;           }