adding cs235

cs235/lab03/sm/ll.cc

@@ -0,0 +1,158 @@
+#include "ll.h"
+
+ll::ll(): _size(0), head(NULL), tail(NULL) {
+}
+
+ll::~ll() {
+    clear();
+}
+
+void ll::insertHead(int value) {
+    if(value < 0 or find(value)) {
+        return;
+    }
+    if(head == NULL) {
+        assert(tail == NULL);
+        assert(_size == 0);
+        head = new node(value);
+        tail = head;
+    }
+    else {
+        node * tmp = head;
+        head = new node(value);
+        head->next = tmp;
+    }
+    _size++;
+}
+
+void ll::insertTail(int value) {
+    if(value < 0 or find(value)) {
+        return;
+    }
+    if(tail == NULL) {
+        assert(head == NULL);
+        assert(_size == 0);
+        tail = new node(value);
+        head = tail;
+    }
+    else {
+        node * tmp = tail;
+        tmp->next = new node(value);
+        tail = tmp->next;
+    }
+    _size++;
+}
+
+void ll::insertAfter(int value, int insertionNode) {
+    if(value < 0 or find(value)) {
+        return;
+    }
+    node * inlist = find(insertionNode);
+    if(not inlist) {
+        return;
+    }
+    node * toinsert = new node(value);
+    if(inlist == tail) {
+        tail = toinsert;
+    }
+    toinsert->next = inlist->next;
+    inlist->next = toinsert;
+    _size++;
+}
+
+void ll::remove(int value) {
+    if(not find(value)) {
+        // should deal with empty list, and not found
+        return;
+    }
+    else if(head == tail) {
+        delete head;
+        head = tail = NULL;
+        _size--;
+    }
+    else {
+        node * cur = head;
+        if(head->value == value) {
+            head = head->next;
+            delete cur;
+            _size--;
+        }
+        else {
+            while(cur) {
+                if(cur->next == NULL) {
+                    // removing end ...
+                    break;
+                }
+                if(cur->next->value == value) {
+                    node * to_remove = cur->next;
+                    if(to_remove == tail) {
+                        tail = cur;
+                    }
+                    cur->next = to_remove->next;
+                    delete to_remove;
+                    _size--;
+                }
+                cur = cur->next;
+            }
+        }
+    }
+}
+
+void ll::clear() {
+    node * tmp = head;
+    while(head) {
+        tmp = head;
+        head = head->next;
+        delete tmp;
+        _size--;
+    }
+    head = tail = NULL;
+    assert(_size == 0);
+}
+
+int ll::at(int index) {
+    if (index >= _size or index < 0) {
+        return -1;
+    }
+    node * tmp = head;
+    for(int i = 0; i < index; i++) {
+        tmp = tmp->next;
+    }
+    if(tmp == NULL) {
+        return -1;
+    }
+    else {
+        return tmp->value;
+    }
+}
+
+int  ll::size() {
+    return _size;
+}
+
+node * ll::find(int value) {
+    node * tmp = head;
+    while(tmp) {
+        if(tmp->value == value) {
+            return tmp;
+        }
+        tmp = tmp->next;
+    }
+    return NULL;
+}
+
+ostream & operator<<(ostream & os, const node & n) {
+    os << n.value;
+    return os;
+}
+
+ostream & operator<<(ostream & os, const ll & l) {
+    os << "ll {(" << l._size << ") ";
+    node * cur = l.head;
+    while (cur) {
+        os << *cur << ", ";
+        cur = cur->next;
+    }
+    os << "}";
+    return os;
+}