LeetCode 169. Majority Element__leetcode

題目

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.

public class Solution169 {    public static void main(String args[]){        Solution169 solution169 = new Solution169();        int nums[] = {3,3,4};        int n = solution169.majorityElement(nums);        System.out.print(n);    }    /**     * 使用hashmap,儲存每一個數出現的次數     * 然後找出出現次數最多的數     *     */    public int majorityElement(int[] nums) {        HashMap<Integer, Integer> hashMap = new HashMap<Integer, Integer>();        for(int i=0;i<nums.length;i++){            if(hashMap.get(nums[i])==null){                hashMap.put(nums[i],1);            }else{                int count = hashMap.get(nums[i]);                hashMap.put(nums[i], ++count);            }        }        int majorityElementIndex=0;        int maxValue=0;        for(int i=0;i<nums.length;i++){            int value = hashMap.get(nums[i]);            if(value>maxValue){                maxValue = value;                majorityElementIndex=nums[i];            }        }        return majorityElementIndex;    }}