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Diffstat (limited to 'I_anno/Programmazione_2/data_structures/circle_list.cc')
-rw-r--r--I_anno/Programmazione_2/data_structures/circle_list.cc118
1 files changed, 62 insertions, 56 deletions
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;
}