Language: C++

#include<cstdio>
#include<cstdlib>
#include<cstring>

struct Node{
  int key;
  Node *Next,*prev;
};

Node *nil;

Node* listSearch(int key){
  Node *cur =nil->next;
  while(cur!=nil&&cur->key!=key){
    cur=cur->next;
  }
  return cur;
}

void init(){
  nil=(Node *)malloc(sizeof(Node));
  nil->next=nil;
  nil->prev=nil;
}

void printList(){
  Node *cur=nil->next;
  int isf=0;
  while(1){
    if(cur==nil)break;
    if(isf++>0)printf(" ");
    printf("%d",cur->key);
    cur=cur-next;
  }
  printf("\n");
}

void deleteNode(Node *t){
  if(t==nil)return;
  t->prev->next=t->next;
  t->next->prev=t->prev;
  free(t);
}

void deleteFirst(){
  deleteNode(nil->next);
}

void deleteLast(){
  deleteNode(nil->prev);
}

void deletekey(int key){
  deleteNode(listSearch(key));
}

void insert(int key){
  Node *x=(Node *)malloc(sizeof(Node);
  x->key=key;
  x->next=nil->next;
  nil->next->prev=x;
  nil->next=x;
  x->prev=nil;
}

int main(){
  int key,n,i;
  int size=0;
  char com[20];
  int np=0,nd=0;
  scanf("%d",&n);
  init();
  for(i=0;i<n;i++){
    scanf("%s%d",com,&key);
    if(com[0]=='i'){insert(key);np++;size++;}
    else if(com[0]=='d'){
      if(strlen(com)>6){
        if(com[6]=='F')deleteFirst();
        else if(com[6]=='L')deleteLast();
      }else{
        deletekey(key);nd++;
      }
      size--;
    }
  }
  printList();
  return 0;
}

Compiler output:
a.cc: In function 'Node* listSearch(int)':
a.cc:13:19: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   13 |   Node *cur =nil->next;
      |                   ^~~~
      |                   Next
a.cc:15:14: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   15 |     cur=cur->next;
      |              ^~~~
      |              Next
a.cc: In function 'void init()':
a.cc:22:8: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   22 |   nil->next=nil;
      |        ^~~~
      |        Next
a.cc: In function 'void printList()':
a.cc:27:18: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   27 |   Node *cur=nil->next;
      |                  ^~~~
      |                  Next
a.cc:33:13: error: 'next' was not declared in this scope
   33 |     cur=cur-next;
      |             ^~~~
a.cc: In function 'void deleteNode(Node*)':
a.cc:40:12: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   40 |   t->prev->next=t->next;
      |            ^~~~
      |            Next
a.cc:40:20: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   40 |   t->prev->next=t->next;
      |                    ^~~~
      |                    Next
a.cc:41:6: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   41 |   t->next->prev=t->prev;
      |      ^~~~
      |      Next
a.cc: In function 'void deleteFirst()':
a.cc:46:19: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   46 |   deleteNode(nil->next);
      |                   ^~~~
      |                   Next
a.cc: In function 'void insert(int)':
a.cc:58:38: error: expected ')' before ';' token
   58 |   Node *x=(Node *)malloc(sizeof(Node);
      |                         ~            ^
      |                                      )
a.cc:60:6: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   60 |   x->next=nil->next;
      |      ^~~~
      |      Next
a.cc:60:16: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   60 |   x->next=nil->next;
      |                ^~~~
      |                Next
a.cc:61:8: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   61 |   nil->next->prev=x;
      |        ^~~~
      |        Next
a.cc:62:8: error: 'struct Node' has no member named 'next'; did you mean 'Next'?
   62 |   nil->next=x;
      |        ^~~~
      |        Next