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]

Answer:

從後向前插入數值

class Solution(object):
    def merge(self, nums1, m, nums2, n):
        """
        :type nums1: List[int]
        :type m: int
        :type nums2: List[int]
        :type n: int
        :rtype: void Do not return anything, modify nums1 in-place instead.
        """
        i=m-1
        j=n-1
        k=m+n-1
        while i>=0 or j>=0:
            if i<0:
                nums1[k]=nums2[j]
                k-=1
                j-=1
                continue
            if j<0:
                nums1[k]=nums1[i]
                k-=1
                i-=1
                continue
            if nums1[i]<nums2[j]:
                nums1[k]=nums2[j]
                k-=1
                j-=1
            elif nums1[i]>=nums2[j]:
                nums1[k]=nums1[i]
                k-=1
                i-=1