"""
合并两个有序数组
"""
from typing import List


class Solution:
    def merge(self, nums1: List[int], m: int, nums2: List[int], n: int) -> None:
        """
        Do not return anything, modify nums1 in-place instead.
        先填充后面的,再填充前面的
        """
        if not nums2:
            return
        len1 = m - 1
        len2 = n - 1
        k = m + n - 1
        while len1 >= 0 and len2 >= 0:
            if nums1[len1] > nums2[len2]:
                nums1[k] = nums1[len1]
                len1 -= 1
            else:
                nums1[k] = nums2[len2]
                len2 -= 1
            k -= 1

        if len2 >= 0:
            # 切片赋值,切片是不包含尾部的
            nums1[:len2 + 1] = nums2[:len2 + 1]
        return nums1


if __name__ == '__main__':
    Solution().merge([1, 2, 3, 0, 0, 0], 3, [2, 5, 6], 3)