题解 | #在两个长度相等的排序数组中找到上中位数#

public class Solution {
    /**
     * find median in two sorted array
     * @param arr1 int整型一维数组 the array1
     * @param arr2 int整型一维数组 the array2
     * @return int整型
     */
    public int findMedianinTwoSortedAray (int[] arr1, int[] arr2) {
        // write code here
        //或者通过遍历两个数组， 找到中间位置，如果arr1 + arr2是奇数，则中位数在中间位置，否则偶数在两个数里找一个最小的
        if(arr1 == null ||arr2 == null || arr1.length != arr2.length){
            return 0;
        }
        int left1 = 0;
        int right1 = arr1.length - 1;
        
        int left2 = 0;
        int right2 = arr2.length - 1;
        
        int mid1 = 0;
        int mid2 = 0;
        int jiou = 0;
        
        while(left1 < right1){
            mid1 = left1 + (right1 - left1) / 2;
            mid2 = left2 + (right2 - left2) / 2;
            
            //是奇数还是偶数 偶数的话
            jiou = (right1 - left1  )%2 ==0 ? 0 : 1;
            if(arr1[mid1] >  arr2[mid2]){
                //中位数在右边
                right1 = mid1;
                left2 = mid2 + jiou;
            }else if(arr1[mid1] < arr2[mid2]){
                right2 = mid2;
                left1 = mid1 +jiou;
            }else{
                //相等  说明 0..mid1  mid2...right2 都是 一样的数字
                return arr1[mid1];
            }
        }
        return Math.min(arr1[left1], arr2[left2]);
    }
}