/* Another play with linked lists. This time I implemented the following functionalities: -show -create a cell -bool include -int length of the list -cell_at -add_f and add_b -delete_at -insert_at -reverse -slice -merge */ #include #include #include typedef struct cell{ int val; struct cell *next; }cell; void show(cell *c){ if(!c){printf("NULL");return;} while(c){ printf("%d\t",c->val); c=c->next; }printf("\n"); } cell *create(int n){ cell*p=(cell*)malloc(sizeof(cell)); p->val=n; p->next=NULL; return p; } int include(cell* c, int n){ while(c){ if(c->val==n) return 1; c=c->next; }return 0; } int len(cell*c){ int l=0; while(c){ l++; c=c->next; }return l; } cell* cell_at(cell*c, int pos){ if(!c) return NULL; int l=len(c); if(pos>l-1) return NULL; if(pos<0) pos=l+pos; cell*p=create(0); cell*tmp=c; while(tmp && pos){ tmp=tmp->next; pos--; } p->val=tmp->val; return p; } cell *add_f(cell* c, int n){ //>> cell*p=create(n); p->next=c; c=p; return c; } cell *add_b(cell* c, int n){ //<< cell*p=create(n); if(!c) return p; cell *tmp=c; while(tmp->next){ tmp=tmp->next; } tmp->next=p; return c; } cell *delete_at(cell*c, int pos){ if(!c) return NULL; int l=len(c); cell*tmp=c->next,*tmp1=c; if(!pos){ free(tmp1); return tmp; }else if(pos<0) pos=l+pos; if(pos>l-1) return NULL; pos--; while(tmp->next && pos>-1){ tmp=tmp->next; tmp1=tmp1->next; pos--; } tmp1->next=tmp->next; free(tmp); return c; } cell *insert_at(cell*c, int pos, int n){ cell*p=create(n); if(!c) return p; int l=len(c); cell*tmp=c->next,*tmp1=c; if(!pos){ c=add_f(c,n); return c; }else if(pos<0) pos=l+pos; if(pos>l-1) return NULL; pos--; while(tmp->next && pos){ tmp=tmp->next; tmp1=tmp1->next; pos--; } tmp1->next=p; p->next=tmp; return c; } cell *reverse(cell*c){ if(!c) return NULL; cell*p=create(c->val); c=c->next; while(c){ p=add_f(p,c->val); c=c->next; } c=p; return c; } cell* slice(cell* c, int start, int end){ if(start>abs(end) || start<0) return NULL; int l=len(c); if(end>l-1) return NULL; int m=end==start; if(end<0) end=l+end; cell*tmp=c; if(!m){ cell*p=cell_at(c,start); while(start){ tmp=tmp->next; start--; } tmp=tmp->next; for(int i=1;i!=end;i++){ p=add_b(p,tmp->val); tmp=tmp->next; } return p; }return cell_at(c,end); } cell* merge(cell*c1, cell*c2){ cell *p=NULL; int l1=len(c1), l2=len(c2); while(l1){ p=add_b(p,c1->val); c1=c1->next; l1--; } while(l2){ p=add_b(p,c2->val); c2=c2->next; l2--; }return p; } int main() { cell *c=create(0); for(int i=1;i!=7;i++) add_b(c,i); delete_at(c,2);//2 insert_at(c,2,42);//put 42 at 2 cell*p=slice(c,1,-2); cell *t=merge(c,p); printf("merge c and p: "); show(t); printf("original list: "); show(c); printf("c from 1 to -2: "); show(p); free(t); free(p); free(c); return 0; }

linked_list_2.c