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]

class Solution {
    public void merge(int[] A, int m, int[] B, int n) {
        int i = m - 1, j = n - 1, k = m + n - 1;
        while
 
(i>=0 && j>=0) A[k--] = (A[i]>B[j]) ? A[i--] : B[j--];
        while(j>=0) A[k--] = B[j--];
    }
}

88. Merge Sorted Array【Easy】【雙指針-不用額外空間歸並兩個有序數組】