Majority Element

题目：

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.

 

 Simple but nlog(n) time complexity

public int majorityElement(int[] num) {
    if (num.length == 1) {
        return num[0];
    }
 
    Arrays.sort(num);
    return num[num.length / 2];
}

Linear Time Majority Vote Algorithm 很高级的样子

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

reference：http://www.programcreek.com/2014/02/leetcode-majority-element-java/

http://www.cs.utexas.edu/~moore/best-ideas/mjrty/