Leetcode: 88. Merge Sorted Array

Description

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.

思路

• 没啥好说的，要么从后往前，要么从前往后，在从前往后的过程中，可能会有一个交换过程，即nums1[i]>nums2[j], 交换两个的值，后i++,j不变

代码

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

    }
};