exp 9: add delete

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

9.c

@@ -34,6 +34,27 @@ void insert(node **root, char *type, char *company, uint yom) {
     insert(&((*root)->right), type, company, yom);
 }
 
+void free_tree(node *n) {
+  if (!n)
+    return;
+
+  free_tree(n->left);
+  free_tree(n->right);
+  free(n);
+}
+
+void delete (node **root, uint yom) {
+  if ((*root)->yom == yom) {
+    free_tree(*root);
+    *root = NULL;
+    return;
+  }
+  if (yom < (*root)->yom)
+    return delete (&((*root)->left), yom);
+
+  return delete (&((*root)->right), yom);
+}
+
 void preorder(node *n) {
   if (!n)
     return;
@@ -61,20 +82,13 @@ void inorder(node *n) {
   inorder(n->right);
 }
 
-void free_tree(node *n) {
-  if (!n)
-    return;
-
-  free_tree(n->left);
-  free_tree(n->right);
-  free(n);
-}
-
 int main() {
   node *root = NULL;
   insert(&root, "A", "Amaang", 4004);
   insert(&root, "Sahi", "Vivek", 2003);
   insert(&root, "How", "Alphonso", 9999);
+  insert(&root, "real", "hmm", 4);
+  delete (&root, 9999);
 
   printf("---------\n");
   printf("Preorder:\n");