new code

Author: STProgrammer

4_0_students_linked_list.cpp

@@ -0,0 +1,59 @@
+#include <iostream>
+
+using std::cout;
+using std::cin;
+using std::endl;
+
+
+struct listNode {
+    int studentNum;
+    int grade;
+    listNode * next;
+};
+
+typedef listNode * studentCollection;
+
+int main()
+{
+    studentCollection sc;
+    listNode* node1 = new listNode;
+    node1->studentNum = 1001;
+    node1->grade = 78;
+    listNode* node2 = new listNode;
+    node2-> studentNum = 1012;
+    node2-> grade = 93; listNode* node3 = new listNode;
+    node3-> studentNum = 1076;
+    node3-> grade = 85;
+    sc = node1;
+    node1-> next = node2;
+    node2-> next = node3;
+    node3-> next = NULL;
+    node1 = node2 = node3 = NULL;
+
+}
+
+
+void addRecord(studentCollection& sc, int stuNum, int gr)
+{
+    listNode * newNode = new listNode;
+    newNode->studentNum = stuNum;
+    newNode->grade = gr;
+    newNode->next = sc;
+    sc = newNode;
+}
+
+double averageRecord(studentCollection sc)
+{
+    int count = 0;
+    double sum = 0;
+    listNode * loopPtr = sc;
+    while (loopPtr != NULL)
+    {
+        sum += loopPtr->grade;
+        count++;
+        loopPtr = loopPtr->next;
+    }
+    double average = sum / count;
+    return average;
+}
+

4_0_variable_length_string.cpp

@@ -0,0 +1,87 @@
+#include <iostream>
+
+using std::cout;
+using std::endl;
+
+typedef char * arrayString;
+
+void append(arrayString &str, char ch);
+void concatenate(arrayString &str1, arrayString str2);
+char characterAt(arrayString str, int position);
+int getLength(arrayString str);
+
+int main()
+{
+    arrayString str = new char[5];
+    str[0] = 'T'; str[1] = 'e'; str[2] = 's'; str[3] = 't'; str[4] = 0;
+    cout << "The string: " << str << endl;
+
+    cout << "Character at position " << 1 << " is " << characterAt(str, 1) << endl;
+
+    cout << "Before append: " << str << endl;
+    append(str, '!');
+    cout << "After append: " << str << endl;
+
+    arrayString str1 = new char[5];
+    str1[0] = 'T'; str1[1] = 'e'; str1[2] = 's'; str1[3] = 't'; str1[4] = 0;
+
+    arrayString strToAdd = new char[4];
+    strToAdd[0] = 'b'; strToAdd[1] = 'e'; strToAdd[2] = 'd'; strToAdd[3] = 0;
+
+    cout << "Before concatenate: " << str1 << endl;
+    cout << "String to add: " << strToAdd << endl;
+    concatenate(str1, strToAdd);
+    cout << "After concatenate: " << str1 << endl;
+    cout << (void*) str1 << " " << (void*)strToAdd << endl;
+
+}
+
+char characterAt(arrayString str, int position)
+{
+    return str[position];
+}
+
+void append(arrayString &str, char ch)
+{
+    int oldLen = getLength(str);
+    arrayString newStr = new char[oldLen + 2];
+
+    for (int i = 0; i < oldLen; i++)
+    {
+        newStr[i] = str[i];
+    }
+    newStr[oldLen] = ch;
+    newStr[oldLen + 1] = 0;
+    delete[] str;
+    str = newStr;
+}
+
+void concatenate(arrayString &str1, arrayString str2)
+{
+    int len1 = getLength(str1);
+    int len2 = getLength(str2);
+    int newLen = len1 + len2;
+    arrayString newStr = new char[newLen+1];
+    for (int i = 0; i < len1; i++)
+    {
+        newStr[i] = str1[i];
+    }
+    for (int i = len1; i < newLen; i++)
+    {
+        newStr[i] = str2[i - len1];
+    }
+    newStr[newLen] = 0;
+    delete[] str1;
+    str1 = newStr;
+}
+
+int getLength(arrayString str)
+{
+    int len = 0;
+    while(str[len] != 0)
+    {
+        len++;
+    }
+    return len;
+}
+