fix: return node removed stack and queue

2 files changed, 17 insertions, 9 deletions

diff --git a/I_anno/Programmazione_2/data_structures/queue.cc b/I_anno/Programmazione_2/data_structures/queue.cc
index c565ac6..e1d4dcb 100644
--- a/I_anno/Programmazione_2/data_structures/queue.cc
+++ b/I_anno/Programmazione_2/data_structures/queue.cc
@@ -34,19 +34,21 @@ public:
         return this;
     }
 
-    queue<T>* dequeue() {
+    node<T>* dequeue() {
         auto iter = _head;
 
-        if(!_head) return this;
+        if(!_head) return nullptr;
         while(iter->next != _tail) {
             iter = iter->next;
         }
 
+        node<T>* elem = iter->next;
+
         delete iter->next;
         iter->next = nullptr;
         _tail = iter;
 
-        return this;
+        return elem;
     }
 
     void print() {
@@ -67,7 +69,10 @@ int main() {
 
     q->dequeue();
     q->enqueue(4)->enqueue(2)->enqueue(8);
-    q->dequeue();
+    q->print();
+    auto e = q->dequeue();
+    if(e)
+        cout << e->value << endl;
     q->enqueue(1);
     q->print();
 
diff --git a/I_anno/Programmazione_2/data_structures/stack.cc b/I_anno/Programmazione_2/data_structures/stack.cc
index 400039d..f1cc7d1 100644
--- a/I_anno/Programmazione_2/data_structures/stack.cc
+++ b/I_anno/Programmazione_2/data_structures/stack.cc
@@ -32,14 +32,14 @@ public:
         return this;
     }
 
-    stack<T>* pop() {
-        if(!_head) return this;
+    node<T>* pop() {
+        if(!_head) return nullptr;
 
         auto old_head = _head;
+        delete _head;
         _head = _head->next;
-        delete old_head;
 
-        return this;
+        return old_head;
     }
 
     void print() {
@@ -59,7 +59,10 @@ int main() {
 
     s->pop();
     s->push(4)->push(2)->push(8);
-    s->pop();
+    s->print();
+    auto e = s->pop();
+    if(e)
+        cout << e->value << endl;
     s->push(1);
     s->print();