剑指offer第五天

import java.util.HashMap;
public class Solution {
    public int MoreThanHalfNum_Solution(int [] array) {
        HashMap<Integer,Integer> map = new HashMap<>();
        int length = array.length;
        if(length == 1) return array[0]; //此处用于当数组只有一个元素的时候，下面的代码对该情况无效
        for(int i : array){
           if(map.containsKey(i)){
               if(map.get(i) == length/2)
                   return i;
               map.put(i,map.get(i) + 1);
               
           }else{
               map.put(i,1);
           }
        }
        return 0;
    }
}

public class Solution {
    public int MoreThanHalfNum_Solution(int [] array) {
        if(array == null || array.length == 0) return 0;
        int length = array.length;
        int result = array[0];
        int times = 1;
        for(int i =1;i<length;i++){
            if(result == array[i])
                times++;
            else if(times == 0){
                result = array[i];
                times =1;
            }else
                times--; 
        }
        if(times == 0) return 0;
        times = 0;
        for(int i =0;i<length;i++){
            if(array[i] == result)
                times++;
        }
        if(times <= length/2)
            result = 0;
        return result;
    }
}