## Easy
## 60ms,faster than 76.15%
## The trick is using sort in Python
class Solution:
    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.
        """

        nums1[m:]=nums2[0:]
        nums1.sort()


## fastest without using sort
## 56ms

class Solution:
    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.
        """
        while m>0 and n>0:
            if nums1[m-1]>nums2[n-1]:
                nums1[m+n-1],nums1[m-1]=nums1[m-1],nums2[n-1]
                m-=1
            else:
                nums1[m+n-1]=nums2[n-1]
                n-=1
        if n>0:## corner case when m=0
            nums1[:n]=nums2[:n]