LeetCode 88. Merge Sorted Array

• By Scarb
• Scarb’s Blog

Tags:
- Array
- Two Pointers

问题描述

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.

解题思路

题意是给出两个排序好的数组和数组的大小，要求合并为一个排序好的数组。
那么就用两个下标指向两个数组的末段，从最后开始比较，将两个下标指向的较大的数放入结果数组并将下标-1.
当一个下标小于0时表示这个数组已经被完全合并，将另一个数组汇入结果数组即可。

参考代码

class Solution {public:    void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {        int ia = m - 1, ib = n - 1, icur = m + n - 1;        while (ia >= 0 && ib >= 0)            nums1[icur--] = nums1[ia] >= nums2[ib] ? nums1[ia--] : nums2[ib--];        while (ib >= 0)            nums1[icur--] = nums2[ib--];    }};