Finishing third problem

lab12/3.c

@@ -1 +1,83 @@
-// wrong problem
+#include <stdio.h>
+#include <stdlib.h>
+
+/* Single Linked list related code */
+typedef struct _selist * Slist;
+
+struct _selist {
+    int el;
+    Slist next;
+};
+
+int head(Slist lst) {
+    return lst->el;
+}
+
+Slist tail(Slist lst) {
+    return lst->next;
+}
+
+Slist insert(int element, Slist current) {
+    Slist head = current;
+
+    while(current->next != head) {
+        current = current->next;
+    }
+    current->next = malloc(sizeof(struct _selist));
+    current = current->next;
+
+    current->el = element;
+    current->next = head;
+    return current;
+}
+
+void print_list(Slist list) {
+    printf("SLIST PRINT\n");
+    Slist head = list;
+    list = list->next;
+    while (list != head) {
+      printf("%d ", list->el);
+      list = list->next;
+    }
+    printf("\n");
+}
+
+size_t size(Slist list) {
+    size_t elements = 0;
+    Slist head = list;
+    list = list->next;
+    while (list != head) {
+        elements += 1;
+        list = list->next;
+    }
+    return elements;
+}
+
+void delete_middle(Slist list) {
+    unsigned long middle = size(list) / 2;
+    Slist prev = list;
+    list = list->next;
+    for (int i = 0; i <= middle; i++) {
+        if (i + 1 == middle) {
+            prev = list;
+        }
+        if (i == middle) {
+            prev->next = list->next;
+            free(list);
+        }
+        list = list->next;
+    }
+}
+
+int main(void) {
+  Slist head = malloc(sizeof(struct _selist));
+  head->next = head;
+  insert(1, head);
+  insert(2, head);
+  insert(3, head);
+  insert(4, head);
+  insert(5, head);
+  delete_middle(head);
+  print_list(head);
+  return 0;
+}