add linked list implementation and demo

wk3/list.cpp

@@ -0,0 +1,74 @@
+#include "list.h"
+
+List::List() {
+    List::InitNodes();
+}
+
+void List::InitNodes() {
+    head = NULL;
+    tail = NULL;
+}
+
+void List::disp() {
+    node *tmp;
+    tmp = head;
+    printf("** BEGIN\n");
+    while(tmp != NULL) {
+        printf("%5d\n", tmp->data);
+        tmp = tmp->next;
+    }
+    printf("** END\n");
+}
+
+void List::addNode(int d) {
+    node *tmp = new node;
+    tmp->data = d;
+    tmp->next = NULL;
+
+    if(head == NULL) {
+        head = tmp;
+        tail = tmp;
+    }
+    else {
+        tail->next = tmp;
+        tail = tail->next;
+    }
+}
+
+void List::addNodeToStart(int d) {
+    node *tmp = new node;
+    tmp -> data = d;
+    tmp -> next = head;
+    head = tmp;
+}
+
+void List::delNode() {
+    node *tmp;
+    tmp = head;
+    while(tmp) {
+        if(tmp -> next == tail) {
+            free(tmp -> next);
+            tail = tmp;
+            tail -> next = NULL;
+        }
+        else {
+            tmp = tmp -> next;
+        }
+    }
+}
+
+void List::delNodeFromStart() {
+    node *tmp;
+    tmp = head;
+    head = head -> next;
+    free(tmp);
+}
+
+void List::clear() {
+    node *tmp;
+    tmp = head;
+    while(tmp) {
+        tmp = tmp -> next;
+        delNodeFromStart();
+    } 
+}

wk3/list.h

@@ -0,0 +1,27 @@
+//list.h
+#include <iostream>
+#include <stdlib.h>
+
+#ifndef list
+#define list
+
+struct node {
+    int data;
+    node *next;
+};
+
+class List {
+    node *head, *tail;
+
+    public:
+        List();
+        void InitNodes();
+        void disp();
+        void addNode(int d);
+        void addNodeToStart(int d);
+        void delNode();
+        void delNodeFromStart();
+        void clear();
+};
+
+#endif

wk3/main.cpp

@@ -0,0 +1,25 @@
+#include "list.h"
+
+int main() {
+    List mylist;
+    mylist.disp();
+    mylist.addNode(1);
+    mylist.disp();
+    mylist.addNode(4);
+    mylist.disp();
+    mylist.addNode(8);
+    mylist.disp();
+    mylist.addNode(8);
+    mylist.disp();
+    mylist.addNodeToStart(8);
+    mylist.disp();
+    mylist.delNodeFromStart();
+    mylist.disp();
+    mylist.delNode();
+    mylist.disp();
+    mylist.addNode(9);
+    mylist.disp();
+    mylist.clear();
+    mylist.disp();
+    return 0;
+}

wk3/makefile

@@ -0,0 +1,11 @@
+CC = clang++
+CFLAGS = -Os -Wall
+
+TARGET = main
+EXTS = list.cpp
+DEPS = list.h
+
+all: build
+
+build: 
+	$(CC) $(CFLAGS) $(EXTS) $(TARGET).cpp -o outf