归并排序 C++实现

#include <iostream>
#include <vector>
#include <algorithm>



using namespace std;

class Solution
{
public:
    void guibing(vector<int>& nums)
    {
        if(nums.size()<2) return ;
        int mid=nums.size()/2;
        vector<int> res1;
        vector<int> res2;
        for(int i=0;i<mid;i++)
        {

            res1.push_back(nums[i]);
        }
        for(int i=mid;i<nums.size();i++)
        {
            res2.push_back(nums[i]);
        }
        guibing(res1);
        guibing(res2);
        nums.clear();
        merge_tow(res1,res2,nums);

    }

private:
    void merge_tow(vector<int> res1,vector<int> res2,vector<int>& nums)
    {
        int i=0;
        int j=0;
        while(i<res1.size() && j<res2.size())
        {
            if(res1[i]<res2[j])
            {
                nums.push_back(res1[i]);
                i++;
            }else
            {
                nums.push_back(res2[j]);
                j++;
            }
        }
        for(;i<res1.size();i++)
        {
            nums.push_back(res1[i]);
        }
        for(;j<res2.size();j++)
        {
            nums.push_back(res2[j]);
        }

    }
};

int main()
{
    vector<int> nums;
    for(int i=0;i<20;i++)
    {
        int x=rand()%100;
        nums.push_back(x);
        cout<<x<<"  ";
    }
    cout<<endl;
    Solution ss;
    ss.guibing(nums);
    for(int i=0;i<nums.size();i++)
    {
        cout<<nums[i]<<"  ";
    }
    cout<<endl;
   
    return 0;
}