Leetcode-88 Arrays: Merge sorted

KEYWORD: Sorted array, three pointers, insert from the back;

原题描述为：

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.

Input:

nums1 = [1,2,3,0,0,0], m = 3

nums2 = [2,5,6],      n = 3

Output: [1,2,2,3,5,6]

Thinking:

- No new array to be created;

-Insert from the back of the nums1, where works as a created new array;

-Two pointers to compare the last element of nums1 and nums2 => put at the find index of nums1

-last index of nums1 = m+n-1;

CODE: