求大佬讲解一下

#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
struct hangban
{
    int daoda;
    int chufa;
    bool nei;
};
/*void maopao(hangban today[],int n)
{
    for(int i=0;i<n;i++)
    {
        bool b = false;
        for(int j=0;j<n-i;j++)
        {
            if(today[j].daoda>today[j+1].daoda)
            {
                swap(today[j],today[j+1]);
                b=true;
            }
        }
        if(b==false)
        {
            break;
        }
    }
}*/

int maopao(hangban today[],int n)
{
    int t=0;
    for(int i=0;i<n;i++)
    {
        if(t<today[i].chufa)
        {
            t=today[i].chufa;
        }
        bool b = false;
        for(int j=0;j<n-i;j++)
        {
            if(today[j].daoda>today[j+1].daoda)
            {
                hangban temp=today[j];
                today[j]=today[j+1];
                today[j+1]=temp;
                b=true;
            }
        }
        if(b==false)
        {
            break;
        }
    }
    return t;
}

int todaytime(hangban today[],int l,int m1,int m2,int t)
{
    int shu=0;
    for(int nei=0;nei<=l;nei++)
    {
        int wai=l-nei;
        int d=0;
        int f=0;
        int temp[100000]={0};
        int t1=0;
        int tag=0;
        for(int i=0;i<t;i++)
        {
            if(today[d].daoda==i)
            {
                if(today[d].nei)
                {
                    if(nei>0)
                    {
                        nei--;
                        tag++;
                        temp[t1]=today[d].chufa;
                        sort(temp,temp+t1-1);
                        t1++;
                        d++;
                    }
                }
                else
                {
                    if(wai>0)
                    {
                        wai--;
                        tag++;
                        temp[t1]=today[d].chufa;
                        sort(temp,temp+t1-1);
                        t1++;
                        d++;
                    }
                }
            }
            
            if(temp[f]==i)
            {
                if(today[d].nei)
                {
                    temp[f]=-1;
                    nei++;
                    f++;
                }
                else
                {
                    temp[f]=-1;
                    wai++;
                    f++;
                }
            }
        }
        if(tag>shu)
        {
            tag=shu;
        }
    }
    return shu;
}
int main()
{
    //freopen("airport.in","r",stdin);
    //freopen("airport.out","w",stdout);
    hangban today[100000];
    int l=0;
    int m1=0;
    int m2=0;
    cin>>l>>m1>>m2;
    
    for(int i=0;i<m1;i++)
    {
        cin>>today[i].daoda>>today[i].chufa;
        today[i].nei=true;
    }
    for(int i=m1;i<m1+m2;i++)
    {
        cin>>today[i].daoda>>today[i].chufa;
        today[i].nei=false;
    }
    
    int t=maopao(today,m1+m2);
    
    int tag=todaytime(today,l,m1,m2,t);
    cout<<tag<<endl;
}