adding classroom code

Class711.cpp

@@ -0,0 +1,61 @@
+//============================================================================
+// Name        : Classroom1.cpp
+// Author      : 
+// Version     :
+// Copyright   : Your copyright notice
+// Description : Hello World in C++, Ansi-style
+//============================================================================
+
+#include <iostream>
+using namespace std;
+
+int mypower(int n, int i) {
+
+	if (i < 0) {
+		return -1;
+	}
+
+	int result = 1;
+
+	while (i > 0) {
+
+		result = n * result; //result *= n
+
+		i--;
+	}
+
+	return result;
+}
+
+int square(int n) {
+
+	return n * n;
+
+}
+
+int main() {
+
+	int val = mypower(2, -4);
+
+	if (val < 0) {
+		cout << "Error"<< endl;
+
+	} else {
+		cout << "Result " << val << endl;
+	}
+
+	cout << "2 ** -4   " << mypower(2, -4) << endl;
+//	cout << "5 ** 0   " << mypower(5, 0) << endl;
+
+/*	int cnt = 1;
+
+	while (cnt <= 10) {
+
+		cout << cnt << "  " << square(cnt) << endl;
+		cnt = cnt + 1; //cnt += 1 or cnt++
+	}
+*/
+	return 0;
+
+
+}

Class712.cpp

@@ -0,0 +1,67 @@
+//============================================================================
+// Name        : Class712.cpp
+// Author      : 
+// Version     :
+// Copyright   : Your copyright notice
+// Description : Hello World in C++, Ansi-style
+//============================================================================
+
+#include <iostream>
+using namespace std;
+
+int sum(int n) {
+
+	int total = 0;
+
+	//Version 1 -- loop
+//	for (int i = 1; i <= n; i++) {
+//		total += i;
+//	}
+	while (n > 0) {
+		total += n;
+		n--;
+	}
+
+	//Version 2 -- closed form
+	//total = n * (n + 1) / 2; //watch out for integer division
+
+	//Version 3 -- recursion
+//	if (n == 0) {
+//		return 0;
+//	} else {
+//		total = sum(n-1) + n;
+//		return total;
+//	}
+
+	return total;
+}
+
+
+int main() {
+
+	int val;
+
+	do {
+		cout << "Enter (neg to stop): ";
+		cin >> val;
+
+		if (val < 0) break;
+
+		cout << "val: " << val << endl;
+		cout << "Result: " << sum(val) << endl << endl;
+		cout << "val: " << val << endl;
+		/*
+		 * The call-by-value parameter passing mechanism is used
+		 * when calling the sum function. Consequently, the value of
+		 * the variable 'val' does not change, even the corresponding
+		 * parameter 'n' in the function is modified.
+		 */
+
+//		if (val >= 0) {
+//			cout << "Result: " << sum(val) << endl << endl;
+//		}
+
+	} while (true);// (val >= 0);
+
+	return 0;
+}

Class713.cpp

@@ -0,0 +1,133 @@
+//============================================================================
+// Name        : Class713.cpp
+// Author      : 
+// Version     :
+// Copyright   : Your copyright notice
+// Description : Hello World in C++, Ansi-style
+//============================================================================
+
+#include <math.h>
+#include <string>
+#include <iostream>
+using namespace std;
+
+#define PI 3.14159265
+
+void sample1( ) {
+	double degree, result;
+	degree = 60.0;
+
+	result = cos (degree * PI/180);
+
+	cout << result << endl;
+
+	return;
+}
+
+void string1( ) {
+
+	string str;
+	int n;
+
+	n = 10;
+	str = "Hello";
+	string space = "";
+
+	for (int i = 0; i < 10; i++) {
+
+		space += "  ";
+
+		cout << space << str << endl;
+        //	cout << str << " " << i << endl;
+	}
+
+	return;
+}
+
+void string2 ( ) {
+
+	string first, last;
+
+	first = "John";
+	last = "Smith";
+
+	string fullname1 = first + " " + last; //John Smith
+	string fullname2 = last + ", " + first; //Smith, John
+	cout << fullname1 << endl << fullname2 << endl;
+
+	string fullname3 = "";
+
+//	fullname3 = first[0];
+//	fullname3 = fullname3 + ". " + last;
+
+
+	fullname3.append(1, first[0]); //change 1 to 3 and see what happens
+	fullname3.append(". " + last);
+    //or
+    //fullname3 = fullname3 + ". " + last;
+
+	cout << fullname3 << endl;
+
+    /*
+     Note:
+
+     We cannot the string concatenation operation as
+
+            string s = first[0] + ". " + last;
+
+     because of data type mismatch. Expression first[0] is char, not string
+     */
+
+	return;
+}
+
+void string3( ) {
+
+    cout << endl << endl;
+
+    string str = "This is a test";
+
+    cout << "'" << str << "' has " << str.size() << " characters." << endl;
+    cout << str.substr(0,4) << endl;
+    cout << "First blank space in the string at position " << str.find(" ") << endl;
+    cout << str << endl;
+
+    return;
+}
+
+void string4( ) {
+	//find the number of blank spaces in a given string
+	string str = "Hello world how  are you  .";
+
+	string searchStr = " ";
+
+	int cnt = 0;
+	int loc = str.find(searchStr);
+
+	while (loc >= 0) { /*not found*/
+
+		cnt++;
+
+		str = str.substr(loc+1,str.size( ));
+		loc = str.find(searchStr);
+	}
+
+	cout << cnt << endl;
+
+	return;
+}
+
+int main() {
+
+	//sample1( );
+
+	//string1( );
+
+	//string2( );
+
+    //string3( );
+
+	string4();
+
+	return 0;
+}