adding cs235

cs235/lab05/linkedlist.cpp

@@ -0,0 +1,102 @@
+#include "linkedlist.h"
+
+linkedlist::linkedlist(): head(NULL) {}
+linkedlist::~linkedlist(){clear();}
+
+void linkedlist::insertHead(int id) {
+    head = new node(id, head);
+}
+
+void linkedlist::insertTail(int id) {
+    if(head == NULL) {
+        insertHead(id);
+        return;
+    }
+    node* node_ptr = head;
+    while(node_ptr != NULL) {
+        if(node_ptr->next == NULL) {
+            node_ptr->next = new node(id, NULL);
+            break;
+        }
+        node_ptr = node_ptr->next;
+    }
+}
+
+void linkedlist::insertAfter(int id, int insertionNode) {
+    node* node_ptr = head;
+    while(node_ptr != NULL) {
+        if(node_ptr->id == insertionNode) {
+            node* temp = new node(id, NULL);
+            temp->next = node_ptr->next;
+            node_ptr->next = temp;
+        }
+        node_ptr = node_ptr->next;
+    }
+}
+
+void linkedlist::remove(int id) {
+    node* node_ptr = head;
+    if(node_ptr->id == id) {
+        node* ptr = head;
+        head = head->next;
+        delete ptr;
+        return;
+    }
+    while(node_ptr != NULL) {
+        if(node_ptr->next == NULL)
+            return;
+        if(node_ptr->next->id == id) {
+            node* ptr = node_ptr->next;
+            node_ptr->next = node_ptr->next->next;
+            delete ptr;
+        }
+        node_ptr = node_ptr->next;
+    }
+}
+
+void linkedlist::clear() {
+    node* node_ptr = head;
+    while(head) {
+        node_ptr = head;
+        head = head->next;
+        delete node_ptr;
+    }
+}
+
+int linkedlist::at(int index) {
+    if(index < 0) {
+        return -1;
+    }
+    if(size() <= index) {
+        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->id;
+}
+
+int linkedlist::size() {
+    int size_of_list = 0;
+    if(head == NULL) {
+        return 0;
+    }
+    node* node_ptr = head;
+    while(node_ptr != NULL) {
+        size_of_list++;
+        node_ptr = node_ptr->next;
+    }
+    return size_of_list;
+}
+
+ostream & operator<<(ostream & os, linkedlist & f) {
+    node* node_ptr = f.head;
+    while(node_ptr != NULL) {
+        os << node_ptr->id << ",";
+        node_ptr = node_ptr->next;
+    }
+    return os;
+}