list.c

#include <stdio.h>
#include <stdlib.h>
#include "list.h"

list newlist(int x, list r) {
  list l = malloc(sizeof(struct intlist));
  l -> value = x;
  l -> rest= r;
  return l;
}
int head(list l){
  return (l->value);
}

list tail(list l){
  return (l->rest);
}

void printlist (list p){
  list l = p;
  printf("%d",l->value);
  l = tail(l);
  while(l!=NULL){
    printf("%d",l->value);
    l = tail(l);
  }
  printf("\n");
}

int elem(int pos, list l){
  list p= l;
  for(int i=1;i<pos;i++)
    p = tail(l);
  return head(p);
}


int length(list l) {
  list p = l;
  int i=0;
  while(p!=NULL){
    i++;
    p = tail(p);
  }
  return i;
}

list append(list l1, list l2){
  list p1=l1;
  list p2=l2;
  if(p1==NULL)
    return p2;
  while(l1->rest!=NULL){
    l1 = tail(l1);
  }
  l1->rest = p2;
  return p1;
}

list add1(int x,list l,int pos){
  if(pos>length(l)){
    printf("Erro: Posição excede o tamanho da lista\n");
    exit(1);
  }
  list p = l;
  for(int i=1;i<pos-1;i++){
    l= tail(l);
  }
  list aux = newlist(x,tail(l));
  l->rest = aux;
  return p;
}

list reverse(list l){
  list nova = NULL;
  list old = l;
  while(old!=NULL){
    nova = append(newlist(head(old),NULL),nova);
    old = tail(old);
  }
  return nova;
}