题解 | #【模板】链表#

#include<bits/stdc++.h>

using namespace std;

int main(){
    int n,x,y;
    list<int> l1;
    cin>>n;
    string s;
    list<int>::iterator iter;

    for(int i=0;i<n;i++)
    {
        int f_insert=0;
        cin>>s;
        if(s=="insert")
        {
            cin>>x>>y;
            for(iter=l1.begin();iter!=l1.end();iter++)
            {
                if(*iter ==x)
                {
                    l1.insert(iter,y);
                    f_insert = 1;
                    break;
                }                   
            }
            if(!f_insert)
                l1.push_back(y);
        }
        else if(s=="delete")
        {
            cin>>x;
            for(iter=l1.begin();iter!=l1.end();iter++)
            {
                if(*iter ==x)
                {
                    l1.erase(iter);
                    break;
                }                   
            }
        }
    }
    if(l1.empty())
    {
        cout<<"NULL";
        return 0;
    }
    for(iter=l1.begin();iter!=l1.end();iter++)
    {
        cout<<*iter<<" ";                  
    }
    
    
    return 0;
}