Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.
Note:
You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from nums2. The number of elements initialized in nums1 and nums2 are m and n respectively.
nums1已经是m+n长度了，不用新申请空间。
从后向前复制。
1 class Solution: 2 def merge(self, l1, m, l2, n): 3 """ 4 :type nums1: List[int] 5 :type m: int 6 :type nums2: List[int] 7 :type n: int 8 :rtype: void Do not return anything, modify nums1 in-place instead. 9 """ 10 i = m - 1 11 j = n - 1 12 13 end = m+n-1 14 while(i >= 0 and j >= 0): 15 if(l1[i] > l2[j]): 16 l1[end] = l1[i] 17 i-=1 18 else: 19 l1[end] = l2[j] 20 j -= 1 21 end -=1 22 23 while (j>=0): 24 l1[end] = l2[j] 25 j -= 1 26 end-=1