[LeetCode]Merge Sorted Array

Merge Sorted Array

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 nums1and nums2 are m and n respectively.

 

从后往前排就不会有插入移位的问题了。

class Solution {
public:
    void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
        int index = m+n-1;
        int index1 = m-1;
        int index2 = n-1;
        while(index1>=0 && index2>=0)
        {
            if(nums1[index1]<nums2[index2])
            {
                nums1[index--] = nums2[index2--];
            }
            else
            {
                nums1[index--] = nums1[index1--];
            }
        }
        while(index1>=0)
        {
            nums1[index--] = nums1[index1--];
        }
        while(index2>=0)
        {
            nums1[index--] = nums2[index2--];
        }
        return;
    }
};