adding cs235

cs235/lab03/Student_Code/linkedlist.cpp

@@ -0,0 +1,158 @@
+#include "linkedlist.h"
+
+linkedlist::linkedlist(): head(NULL) {}
+linkedlist::~linkedlist(){clear();}
+
+bool linkedlist::is_it_zero(int value) {
+    if(value < 0)
+        return false;
+    else
+        return true;
+}
+
+bool linkedlist::has_a(int value) {
+  //  cout << "has_a(" << value << ")" << endl;
+    node* node_ptr = head;
+    if(head == NULL)
+        return false;
+    while(node_ptr != NULL) {
+        if(node_ptr->value == value)
+            return true;
+        node_ptr = node_ptr->next;
+    }
+    return false;
+}
+
+void linkedlist::insertHead(int value) {
+   // cout << "inserthead(" << value << ")" << endl;
+   // cout << *this << endl;
+    if(!is_it_zero(value))
+        return;
+    if(has_a(value))
+        return;
+    head = new node(value, head);
+  //  cout << *this << endl << endl;
+}
+
+void linkedlist::insertTail(int value) {
+   // cout << "insertTail(" << value << ")" << endl;
+   // cout << *this << endl;
+    if(!is_it_zero(value))
+        return;
+    if(has_a(value))
+        return;
+    if(head == NULL) {
+        insertHead(value);
+        return;
+    }
+    node* node_ptr = head;
+    while(node_ptr != NULL) {
+        if(node_ptr->next == NULL) {
+            node_ptr->next = new node(value, NULL);
+            break;
+        }
+        node_ptr = node_ptr->next;
+    }
+  //  cout << *this << endl << endl;
+}
+
+void linkedlist::insertAfter(int value, int insertionNode) {
+  //  cout << "insertAfter(" << value << ", insertionNode" << insertionNode << ")" << endl;
+  //  cout << *this << endl;
+    if(value < 0 || insertionNode < 0) {
+        //cout << "first check" << endl;
+        return;
+    }
+    if(has_a(value) || !has_a(insertionNode)) {
+        //cout << "failing" << endl;
+        return;
+    }
+    node* node_ptr = head;
+    while(node_ptr != NULL) {
+        if(node_ptr->value == insertionNode) {
+            node* temp = new node(value, NULL);
+            temp->next = node_ptr->next;
+            node_ptr->next = temp;
+        }
+        node_ptr = node_ptr->next;
+    }
+  //  cout << *this << endl << endl;
+}
+
+void linkedlist::remove(int value) {
+ //   cout << "remove(" << value << ")" << endl;
+ //   cout << *this << endl;
+    if(!is_it_zero(value))
+        return;
+    if(!has_a(value))
+        return;
+    node* node_ptr = head;
+    if(node_ptr->value == value) {
+        //cout << "first" << endl;
+        node* ptr = head;
+        head = head->next;
+        delete ptr;
+        return;
+    }
+    while(node_ptr != NULL) {
+        if(node_ptr->next == NULL)
+            return;
+        if(node_ptr->next->value == value) {
+            node* ptr = node_ptr->next;
+            node_ptr->next = node_ptr->next->next;
+            delete ptr;
+        }
+        node_ptr = node_ptr->next;
+    }
+ //   cout << *this << endl << endl;
+}
+
+void linkedlist::clear() {
+ //   cout << "clear()" << endl;
+    node* node_ptr = head;
+    while(head) {
+        node_ptr = head;
+        head = head->next;
+        delete node_ptr;
+    }
+}
+
+int linkedlist::at(int index) {
+  //  cout << *this << endl;
+  //  cout << "at(" << index << ")" << endl;
+    if(index < 0) {
+        //cout << "is it zero" << endl;
+        return -1;
+    }
+    if(size() <= index) {
+       // cout << "this is the index=" << index << " size(" << size() << ")"<<endl;
+        return -1;
+    }
+    node* node_ptr = head;
+    for(int i = 0; i < index; i++){
+        node_ptr = node_ptr->next;
+    }
+    if(head == NULL)
+        return -1;
+    return node_ptr->value;
+}
+
+int linkedlist::size() {
+    int size_of_list = 0;
+    node* node_ptr = head;
+    while(node_ptr != NULL) {
+        size_of_list++;
+        node_ptr = node_ptr->next;
+    }
+   // cout << "size(" << size_of_list << ")" << endl;
+    return size_of_list;
+}
+
+ostream & operator<<(ostream & os, linkedlist & f) {
+    node* node_ptr = f.head;
+    while(node_ptr != NULL) {
+        os << node_ptr->value << ",";
+        node_ptr = node_ptr->next;
+    }
+    return os;
+}