88. Merge Sorted Array

Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.

Note:

The number of elements initialized in nums1 and nums2 are m and n respectively.

You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from nums2.

Example:
Input:
nums1 = [1,2,3,0,0,0], m = 3
nums2 = [2,5,6],       n = 3
Output: [1,2,2,3,5,6]

难度：easy

题目：

给定两个有序整数数组nums1 和 nums2, 合并两数组。

注意：

nums1和nums2是单独实例化的两个数组长度为m和n。假定nums1拥有足够的空间（大于m+n)来存放nums2中的所有元素。

思路：从后向前处理

Runtime: 2 ms, faster than 100.00% of Java online submissions for Merge Sorted Array.

Memory Usage: 26.4 MB, less than 93.33% of Java online submissions for Merge Sorted Array.

class Solution {
    public void merge(int[] nums1, int m, int[] nums2, int n) {
        int end = m + n - 1;
        int ml = m - 1, nl = n - 1;
        while (ml >= 0 && nl >= 0) {
            nums1[end--] = nums1[ml] > nums2[nl] ? nums1[ml--] : nums2[nl--];
        }
        
        while (nl >= 0) {
            nums1[end--] = nums2[nl--];
        }
    }
}