From e2e7a2e4fa6e50397da79da9cb8c2aec76779575 Mon Sep 17 00:00:00 2001
From: Santo Cariotti <dcariotti24@gmail.com>
Date: Wed, 13 May 2020 20:21:54 +0200
Subject: fix: improve code quality for data structures

---
 .../data_structures/circle_double_list.cc          | 126 +++++++++------------
 .../data_structures/circle_list.cc                 | 118 ++++++++++---------
 I_anno/Programmazione_2/data_structures/list.cc    |  60 +++++-----
 .../data_structures/list_double.cc                 |  76 +++++--------
 I_anno/Programmazione_2/data_structures/queue.cc   |   2 +
 I_anno/Programmazione_2/data_structures/stack.cc   |   2 +
 6 files changed, 179 insertions(+), 205 deletions(-)

(limited to 'I_anno')

diff --git a/I_anno/Programmazione_2/data_structures/circle_double_list.cc b/I_anno/Programmazione_2/data_structures/circle_double_list.cc
index efd0f4a..e50456b 100644
--- a/I_anno/Programmazione_2/data_structures/circle_double_list.cc
+++ b/I_anno/Programmazione_2/data_structures/circle_double_list.cc
@@ -16,98 +16,61 @@ public:
     list() : _head{nullptr} {}
 
     ~list() {
-        while(_head != nullptr) {
-            node<T>* tmp = _head->next;
-            delete tmp;
-            _head = tmp;
-        }
-    }
-
-    node<T>* last_element() {
         node<T>* iter = _head;
-        while(iter && iter->next != _head) {
+        while(iter->next != _head) {
+            node<T>* tmp = iter;
+            delete tmp;
             iter = iter->next;
         }
-
-        return iter;
-    }
-
-    node<T>* search(T val) {
-        if(_head == nullptr) return nullptr;
-
-        node<T>* iter = _head;
-        if(iter->value == val) 
-            return iter;
-
-        while(iter && iter->value != val) {
-            iter = iter->next;
-            if(iter == _head) break;
-        }
-
-        if(iter == _head) return nullptr;
-
-        return iter;
+        node<T>* tmp = iter;
+        delete tmp;
     }
 
     list* push_front(T val) {
-        auto elem = last_element();
-        if(_head == nullptr) {
+        auto elem = _last();
+        if(!_head) {
             _head = new node<T>{val, nullptr, nullptr};
             _head->prev = _head->next = _head;
         } else {
             _head = new node<T>{val, elem, _head};
-            elem->next = _head;
-            _head->next->prev = _head;
+            elem->next = _head->next->prev = _head;
         }
 
         return this;
     }
 
     list* push_back(T val) {
-        if(_head == nullptr) {
-            _head = new node<T>{val, nullptr, nullptr};
-            _head->prev = _head->next = _head;
-        } else {
-            auto last_e = last_element();
-            last_e->next = new node<T>{val, last_e, _head};
-            _head->prev = last_e->next;
-        }
+        if(!_head) return this->push_front(val);
+
+        auto last_e = _last();
+        last_e->next = new node<T>{val, last_e, _head};
+        _head->prev = last_e->next;
 
         return this;
     }
 
     list* push_after_value(T val, T newval) {
-        if(!search(val)) return this;
-
-        node<T>* iter = _head;
-        while(iter && iter->value != val)
-            iter = iter->next;
-
-        if(iter == nullptr)
-            return this->push_front(newval);
-
-        node<T>* nod = new node<T>{newval, iter, iter->next};
-        iter->next = nod;
-        nod->next->prev = nod;
+        node<T>* iter = _search(val);
+        if(iter) {
+            node<T>* nod = new node<T>{newval, iter, iter->next};
+            iter->next = nod;
+            nod->next->prev = nod;
+        }
 
         return this;
     }
 
     list* push_before_value(T val, T newval) {
-        if(!search(val)) return this;
+        node<T>* elem = _search(val);
+        if(!elem) return this;
 
         node<T>* iter = _head;
 
         if(iter->value == val)
             return this->push_front(newval);
 
-        while(iter && iter->next && iter->next->value != val) {
+        while(iter->next != elem)
             iter = iter->next;
-            if(iter == _head) break;
-        }
-
-        if(iter == nullptr)
-            return this->push_front(newval);
 
         node<T>* nod = new node<T>{newval, iter, iter->next};
         iter->next = nod;
@@ -117,19 +80,14 @@ public:
     }
 
     list* pop(int val) {
-
-        if(_head == nullptr)
-            return this;
-        else if(_head->value == val) 
-            return pop_front();
-
-        if(!search(val)) return this;
+        node<T>* elem = _search(val);
+        if(!elem) return this;
 
         node<T>* iter = _head;
-        while(iter && iter->next && iter->next->value != val) {
+        if(iter == elem) return this->pop_front();
+
+        while(iter->next != elem)
             iter = iter->next;
-            if(iter == _head) break;
-        }
 
         node<T>* temp = iter->next;
         iter->next = iter->next->next;
@@ -140,10 +98,10 @@ public:
     }
 
     list* pop_front() {
-        if(_head == nullptr)
+        if(!_head)
             return this;
 
-        auto last_e = last_element();
+        auto last_e = _last();
         node<T>* elem = _head;
         _head = _head->next;
         _head->prev = last_e;
@@ -154,11 +112,11 @@ public:
     }
 
     list* pop_back() {
-        if(_head == nullptr)
+        if(!_head)
             return this;
 
         node<T>* iter = _head;
-        auto last_e = last_element();
+        auto last_e = _last();
 
         if(last_e == _head) {
             delete iter;
@@ -187,6 +145,27 @@ public:
         }
     }
 private:
+    node<T>* _last() {
+        node<T>* iter = _head;
+        while(iter && iter->next != _head) {
+            iter = iter->next;
+        }
+
+        return iter;
+    }
+
+    node<T>* _search(T val) {
+        node<T>* iter = _head;
+        if(iter->value == val) return iter;
+
+        while(iter && iter->value != val) {
+            iter = iter->next;
+            if(iter == _head) return nullptr;
+        }
+
+        return iter;
+    }
+
     node<T>* _head;
 };
 
@@ -208,5 +187,6 @@ int main() {
     l->pop(2);
     l->print(); cout << '\n';
 
+    delete l;
     return 0;
 }
diff --git a/I_anno/Programmazione_2/data_structures/circle_list.cc b/I_anno/Programmazione_2/data_structures/circle_list.cc
index b6be463..2143ac1 100644
--- a/I_anno/Programmazione_2/data_structures/circle_list.cc
+++ b/I_anno/Programmazione_2/data_structures/circle_list.cc
@@ -15,42 +15,20 @@ public:
     list() : _head{nullptr} {}
 
     ~list() {
-        while(_head != nullptr) {
-            node<T>* tmp = _head->next;
-            delete tmp;
-            _head = tmp;
-        }
-    }
-
-    node<T>* last_element() {
         node<T>* iter = _head;
-        while(iter && iter->next != _head) {
-            iter = iter->next;
-        }
-
-        return iter;
-    }
-
-    node<T>* search(T val) {
-        if(_head == nullptr) return nullptr;
-
-        node<T>* iter = _head;
-        if(iter->value == val) 
-            return iter;
-
-        while(iter && iter->value != val) {
+        while(iter->next != _head) {
+            node<T>* tmp = iter;
+            delete tmp;
             iter = iter->next;
         }
-
-        if(iter == _head) return nullptr;
-
-        return iter;
+        node<T>* tmp = iter;
+        delete tmp;
     }
 
     list* push_front(T val) {
-        auto elem = last_element();
+        auto elem = _last();
         _head = new node<T>{val, _head};
-        if(elem == nullptr)
+        if(!elem)
             elem = _head;
 
         elem->next = _head;
@@ -59,57 +37,61 @@ public:
     }
 
     list* push_back(T val) {
-        node<T>* iter = _head;
-        if(_head == nullptr) {
-            _head = new node<T>{val, _head};
-        } else {
-            while(iter->next != nullptr && iter->next != _head) {
-                iter = iter->next;
-            }
-            iter->next = new node<T>{val, _head};
-        }
+        if(!_head) return this->push_front(val);
+
+        auto last_e = _last();
+        last_e->next = new node<T>{val, _head};
+
         return this;
     }
 
     list* push_after_value(T val, T newval) {
-        if(!search(val)) return this;
+        node<T>* iter = _search(val);
+        if(iter)
+            iter->next = new node<T>{newval, iter->next};
+
+        return this;
+    }
+
+    list* push_before_value(T val, T newval) {
+        node<T>* elem = _search(val);
+        if(!elem) return this;
 
         node<T>* iter = _head;
-        while(iter && iter->value != val)
-            iter = iter->next;
 
-        if(iter == nullptr)
+        if(iter->value == val)
             return this->push_front(newval);
 
+        while(iter->next != elem)
+            iter = iter->next;
+
         iter->next = new node<T>{newval, iter->next};
 
         return this;
     }
 
-    list* push_before_value(T val, T newval) {
-        if(!search(val)) return this;
+    list* pop(int val) {
+        node<T>* elem = _search(val);
+        if(!elem) return this;
 
         node<T>* iter = _head;
+        if(iter == elem) return this->pop_front();
 
-        if(iter->value == val)
-            return this->push_front(newval);
-
-        while(iter && iter->next && iter->next->value != val)
+        while(iter->next != elem)
             iter = iter->next;
 
-        if(iter == nullptr)
-            return this->push_front(newval);
-
-        iter->next = new node<T>{newval, iter->next};
+        node<T>* temp = iter->next;
+        iter->next = iter->next->next;
+        delete temp;
 
         return this;
     }
 
     list* pop_front() {
-        if(_head == nullptr)
+        if(!_head)
             return this;
 
-        auto last_e = last_element();
+        auto last_e = _last();
 
         if(last_e == _head) {
             delete _head;
@@ -125,11 +107,11 @@ public:
     }
 
     list* pop_back() {
-        if(_head == nullptr)
+        if(!_head)
             return this;
 
         node<T>* iter = _head;
-        auto last_e = last_element();
+        auto last_e = _last();
 
         if(last_e == _head) {
             delete iter;
@@ -155,6 +137,27 @@ public:
         }
     }
 private:
+    node<T>* _last() {
+        node<T>* iter = _head;
+        while(iter && iter->next != _head) {
+            iter = iter->next;
+        }
+
+        return iter;
+    }
+
+    node<T>* _search(T val) {
+        node<T>* iter = _head;
+        if(iter->value == val) return iter;
+
+        while(iter && iter->value != val) {
+            iter = iter->next;
+            if(iter == _head) return nullptr;
+        }
+
+        return iter;
+    }
+
     node<T>* _head;
 };
 
@@ -178,6 +181,9 @@ int main() {
     l->print(); cout << endl;
     l->push_before_value(3, 5);
     l->print(); cout << endl;
+    l->pop(5);
+    l->print(); cout << endl;
 
+    delete l;
     return 0;
 }
diff --git a/I_anno/Programmazione_2/data_structures/list.cc b/I_anno/Programmazione_2/data_structures/list.cc
index 2aa97de..8ddcbf9 100644
--- a/I_anno/Programmazione_2/data_structures/list.cc
+++ b/I_anno/Programmazione_2/data_structures/list.cc
@@ -15,7 +15,7 @@ public:
     list() : _head{nullptr} {}
 
     ~list() {
-        while(_head != nullptr) {
+        while(_head) {
             node<T>* tmp = _head->next;
             delete tmp;
             _head = tmp;
@@ -29,57 +29,50 @@ public:
     }
 
     list* push_back(T val) {
+        if(!_head) return this->push_front(val);
+
         node<T>* iter = _head;
-        if(_head == nullptr) {
-            _head = new node<T>{val, nullptr};
-        } else {
-            while(iter->next != nullptr) {
-                iter = iter->next;
-            }
-            iter->next = new node<T>{val, nullptr};
+        while(iter->next) {
+            iter = iter->next;
         }
+        iter->next = new node<T>{val, nullptr};
 
         return this;
     }
 
     list* push_after_value(T val, T newval) {
-        node<T>* iter = _head;
-        while(iter && iter->value != val)
-            iter = iter->next;
-
-        if(iter == nullptr)
-            return this->push_front(newval);
-
-        iter->next = new node<T>{newval, iter->next};
+        node<T>* iter = _search(val);
+        if(iter)
+            iter->next = new node<T>{newval, iter->next};
 
         return this;
     }
 
     list* push_before_value(T val, T newval) {
+        node<T>* elem = _search(val);
+        if(!elem) return this;
+
         node<T>* iter = _head;
 
         if(iter->value == val)
             return this->push_front(newval);
 
-        while(iter && iter->next && iter->next->value != val)
+        while(iter->next != elem)
             iter = iter->next;
 
-        if(iter == nullptr)
-            return this->push_front(newval);
-
         iter->next = new node<T>{newval, iter->next};
 
         return this;
     }
 
     list* pop(int val) {
-        if(_head == nullptr)
-            return this;
-        else if(_head->value == val) 
-            return pop_front();
+        node<T>* elem = _search(val);
+        if(!elem) return this;
 
         node<T>* iter = _head;
-        while(iter && iter->next && iter->next->value != val)
+        if(iter == elem) return this->pop_front();
+
+        while(iter->next != elem)
             iter = iter->next;
 
         node<T>* temp = iter->next;
@@ -90,7 +83,7 @@ public:
     }
 
     list* pop_front() {
-        if(_head == nullptr)
+        if(!_head)
             return this;
 
         node<T>* elem = _head;
@@ -101,7 +94,7 @@ public:
     }
 
     list* pop_back() {
-        if(_head == nullptr)
+        if(!_head)
             return this;
 
         node<T>* iter = _head;
@@ -110,7 +103,7 @@ public:
             iter = iter->next;
         }
 
-        if(iter->next == nullptr) {
+        if(!iter->next) {
             delete iter;
             _head = nullptr;
         } else if(iter->next->next) {
@@ -126,12 +119,20 @@ public:
 
     void print() {
         node<T>* iter = _head;
-        while(iter != nullptr) {
+        while(iter) {
             cout << iter->value << ' ';
             iter = iter->next;
         }
     }
 private:
+    node<T>* _search(T value) {
+        node<T>* iter = _head;
+        while(iter && iter->value != value)
+            iter = iter->next;
+
+        return iter;
+    }
+
     node<T>* _head;
 };
 
@@ -158,5 +159,6 @@ int main() {
     l->pop(1);
     l->print(); cout << endl;
 
+    delete l;
     return 0;
 }
diff --git a/I_anno/Programmazione_2/data_structures/list_double.cc b/I_anno/Programmazione_2/data_structures/list_double.cc
index 9dc11b7..79cd8c3 100644
--- a/I_anno/Programmazione_2/data_structures/list_double.cc
+++ b/I_anno/Programmazione_2/data_structures/list_double.cc
@@ -23,22 +23,6 @@ public:
         }
     }
 
-    node<T>* search(T val) {
-        if(_head == nullptr) return nullptr;
-
-        node<T>* iter = _head;
-        if(iter->value == val) 
-            return iter;
-
-        while(iter && iter->value != val) {
-            iter = iter->next;
-        }
-
-        if(iter == _head) return nullptr;
-
-        return iter;
-    }
-
     list* push_front(T val) {
         if(_head == nullptr) {
             _head = new node<T>{val, nullptr, nullptr};
@@ -51,50 +35,40 @@ public:
     }
 
     list* push_back(T val) {
+        if(!_head) return this->push_front(val);
+
         node<T>* iter = _head;
-        if(_head == nullptr) {
-            _head = new node<T>{val, nullptr, nullptr};
-        } else {
-            while(iter->next != nullptr) {
-                iter = iter->next;
-            }
-            iter->next = new node<T>{val, iter, nullptr};
+        while(iter->next) {
+            iter = iter->next;
         }
+        iter->next = new node<T>{val, iter, nullptr};
 
         return this;
     }
 
     list* push_after_value(T val, T newval) {
-        if(!search(val)) return this;
-
-        node<T>* iter = _head;
-        while(iter && iter->value != val)
-            iter = iter->next;
-
-        if(iter == nullptr)
-            return this->push_front(newval);
-
-        node<T>* nod = new node<T>{newval, iter, iter->next};
-        iter->next = nod;
-        nod->next->prev = nod;
+        node<T>* elem = _search(val);
+        if(elem) {
+            node<T>* nod = new node<T>{newval, elem, elem->next};
+            elem->next = nod;
+            nod->next->prev = nod;
+        }
 
         return this;
     }
 
     list* push_before_value(T val, T newval) {
-        if(!search(val)) return this;
+        node<T>* elem = _search(val);
+        if(!elem) return this;
 
         node<T>* iter = _head;
 
         if(iter->value == val)
             return this->push_front(newval);
 
-        while(iter && iter->next && iter->next->value != val)
+        while(iter->next != elem)
             iter = iter->next;
 
-        if(iter == nullptr)
-            return this->push_front(newval);
-
         node<T>* nod = new node<T>{newval, iter, iter->next};
         iter->next = nod;
         nod->next->prev = nod;
@@ -103,15 +77,13 @@ public:
     }
 
     list* pop(int val) {
-        if(_head == nullptr)
-            return this;
-        else if(_head->value == val) 
-            return pop_front();
-
-        if(!search(val)) return this;
+        node<T>* elem = _search(val);
+        if(!elem) return this;
 
         node<T>* iter = _head;
-        while(iter && iter->next && iter->next->value != val)
+        if(iter == elem) return this->pop_front();
+
+        while(iter->next != elem)
             iter = iter->next;
 
         node<T>* temp = iter->next;
@@ -168,6 +140,14 @@ public:
         }
     }
 private:
+    node<T>* _search(T value) {
+        node<T>* iter = _head;
+        while(iter && iter->value != value)
+            iter = iter->next;
+
+        return iter;
+    }
+
     node<T>* _head;
 };
 
@@ -194,5 +174,7 @@ int main() {
     l->pop(2);
     l->print(); cout << endl;
 
+    delete l;
+
     return 0;
 }
diff --git a/I_anno/Programmazione_2/data_structures/queue.cc b/I_anno/Programmazione_2/data_structures/queue.cc
index 476074f..c565ac6 100644
--- a/I_anno/Programmazione_2/data_structures/queue.cc
+++ b/I_anno/Programmazione_2/data_structures/queue.cc
@@ -12,6 +12,7 @@ template<class T>
 class queue {
 public:
     queue() : _head{nullptr} {}
+
     ~queue() {
         auto iter = _head;
         while(iter) {
@@ -19,6 +20,7 @@ public:
             iter = iter->next;
         }
     }
+
     queue<T>* enqueue(T val) {
 
         if(!_head) {
diff --git a/I_anno/Programmazione_2/data_structures/stack.cc b/I_anno/Programmazione_2/data_structures/stack.cc
index efdb939..400039d 100644
--- a/I_anno/Programmazione_2/data_structures/stack.cc
+++ b/I_anno/Programmazione_2/data_structures/stack.cc
@@ -12,6 +12,7 @@ template<class T>
 class stack {
 public:
     stack() : _head{nullptr} {}
+
     ~stack() {
         auto iter = _head;
         while(iter) {
@@ -19,6 +20,7 @@ public:
             iter = iter->next;
         }
     }
+
     stack<T>* push(T val) {
 
         if(!_head) {
-- 
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