LeetCode.88.Merge Sorted Array

原題鏈接：Merge Sorted Array

題目內容：
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]

題目翻譯：
給定兩個有序整數數組nums1和nums2，將nums2合併到nums1中得到一個有序數組。
注意：假定nums1有足夠的空間（其大小大於等於m+n）來存放nums2的元素。nums1和nums2初始時分別有m和n個元素。

Tips：從合併後nums1的尾部元素開始，依次向前確定每個元素的值應該是多少。

Python

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

C++

class Solution {
public:
    void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
        int p = m-1, q = n-1;
        while (p >= 0 && q >= 0){
            if (nums1[p] > nums2[q]){
                nums1[p+q+1] = nums1[p];
                p -= 1;
            }
            else{
                nums1[p+q+1] = nums2[q];
                q -= 1;
            }
        }
        for(int i=0; i<=q; i++){
            nums1[i] = nums2[i];
        }
    }
};