# 88. Merge Sorted Array 合并两个有序数组

@TOC

## # 题目描述

Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.

Note:

1. The number of elements initialized in nums1 and nums2 are m and n respectively.
2. 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]
``````

## # 解题方法

``````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.
"""
while m > 0 and n > 0:
if nums1[m - 1] > nums2[n -1]:
nums1[m + n - 1] = nums1[m - 1]
m -= 1
else:
nums1[m + n - 1] = nums2[n - 1]
n -= 1
nums1[:n] = nums2[:n]
``````

``````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, j = m - 1, n - 1
k = m + n - 1
while i >= 0 and j >= 0:
if nums1[i] > nums2[j]:
nums1[k] = nums1[i]
i -= 1
else:
nums1[k] = nums2[j]
j -= 1
k -= 1
while j >= 0:
nums1[k] = nums2[j]
j -= 1
k -= 1
``````

### # 新建数组

``````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.
"""
nums = [n1 for i, n1 in enumerate(nums1) if i < m] + [n2 for i, n2 in enumerate(nums2) if i < n]
nums.sort()
for i, num in enumerate(nums):
nums1[i] = num
``````

## # 日期

2017 年 8 月 21 日 2018 年 11 月 24 日 —— 周六快乐