leetcode - 4. Median of Two Sorted Arrays

Degree

Easy ★ (*´╰╯`๓)♬

Description:

There are two sorted arrays nums1 and nums2 of size m and n respectively.
Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).

Example1:

nums1 = [1, 3]
nums2 = [2]

The median is 2.0

Example2:

nums1 = [1, 2]
nums2 = [3, 4]

The median is (2 + 3)/2 = 2.5

Ideas

• 将两个数组合并成一个数组并按大小顺序排序
• 选取数组的中间两个数或一个数
• 算出平均数

Code

/**
 * @param {number[]} nums1
 * @param {number[]} nums2
 * @return {number}
 */
var findMedianSortedArrays = function(nums1, nums2) {
    function compare(val1,val2){
        return val1-val2;
    };
    let nums3 = nums1.concat(nums2).sort(compare);
    let lowMiddle = Math.floor((nums3.length - 1) / 2);
    let highMiddle = Math.ceil((nums3.length - 1) / 2);
    let median = (nums3[lowMiddle] + nums3[highMiddle]) / 2;
    return median;
};