add single linked list

Author: DanOlaru

.vscode/settings.json

@@ -2,6 +2,7 @@
   "files.associations": {
     "ostream": "cpp",
     "string": "cpp",
-    "iostream": "cpp"
+    "iostream": "cpp",
+    "cstdlib": "cpp"
   }
 }

dataStructures/dataStructures.h

@@ -0,0 +1,109 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+// #define NULL nullptr
+
+typedef int item_type;
+
+typedef struct LinkedList
+{
+  item_type item;
+  struct LinkedList *next;
+} list;
+
+LinkedList *search_recursive(LinkedList *list, item_type quarry)
+{
+  if (list == NULL)
+    return NULL;
+
+  if (list->item == quarry)
+  {
+    return list;
+  }
+  else
+  {
+    return search_recursive(list->next, quarry);
+  }
+}
+
+LinkedList *search(LinkedList *list, item_type quarry)
+{
+  LinkedList *current = list;
+
+  while ((current->item != quarry) && (current->next != NULL))
+  {
+    current = current->next;
+  }
+  if (current->item == quarry)
+  {
+    return current;
+  }
+
+  return NULL;
+}
+
+void insert(LinkedList **list, item_type new_element)
+{
+  LinkedList *new_list_node = (LinkedList *)malloc(sizeof(LinkedList));
+
+  new_list_node->item = new_element;
+  new_list_node->next = *list;
+
+  *list = new_list_node;
+}
+
+LinkedList *find_predecessor(LinkedList *list, item_type quarry)
+{
+  LinkedList *current = list;
+
+  while (current->next)
+  {
+    if ((current->next)->item == quarry)
+    {
+      return current;
+    }
+    else
+    {
+      current = current->next;
+    }
+  }
+}
+
+int delete_element(LinkedList *list, item_type target)
+{
+
+  LinkedList *target_elem = search_recursive(list, target);
+
+  LinkedList *predecessor = find_predecessor(list, target);
+
+  if (target_elem != NULL)
+  {
+    if (predecessor == NULL)
+    {
+      list = list->next;
+    }
+    else
+    {
+      predecessor->next = predecessor->next->next;
+    }
+    free(target_elem);
+    return 1;
+  }
+
+  return 0;
+}
+
+void display_list(LinkedList **list)
+{
+  LinkedList *current = *list;
+
+
+  printf("\n");
+  printf("Printing linked list \n");
+  printf("\n");
+  while (current != NULL)
+  {
+    printf("%d ", current->item);
+    current = current->next;
+  }
+}

dataStructures/main

@@ -0,0 +1,43 @@
+#include "dataStructures.h"
+
+int main(int argc, char const *argv[])
+{
+  int input_array[] = {1, 4, 3, 2, 6, 7};
+
+  LinkedList *list = (LinkedList *)malloc(sizeof(LinkedList));
+  // LinkedList *list;
+  list->item = input_array[0];
+  printf("%d ", input_array[0]);
+
+  for (int i = 1; i < 6; i++)
+  {
+    insert(&list, input_array[i]);
+  }
+
+  display_list(&list);
+  printf("\n");
+
+  printf("20 exists ?");
+
+  printf("\n");
+  if (search(list, 20)) {
+    printf("YES");
+  } else {
+    printf("NO");
+  }
+  printf("\n");
+
+  LinkedList *pred = find_predecessor(list, 2);
+  if (pred != NULL) {
+    printf("FOUND %d", pred->item);
+  } else {
+    printf("NOT FOUND");
+  }
+  printf("\n");
+
+  delete_element(list, 2);
+  display_list(&list);
+  printf("\n");
+
+  return 0;
+}