Mid-Term Exam (2)
Introduction to Computer Science
NCNU CSIE

Date: November 21th, 2007
Time: 13:10-15:00
Open book; turn off computer & mobile phone

1. What will be the output of the following program?

   #include <iostream>
   int main()
   {
           const int MAX = 100;
           int i = 1, sum = 0;
   loop:   sum += i;               // Add current value of i to sum
           if (i++ <= MAX)
                   goto loop;      // Go back to loop
           std::cout << std::endl << "sum = " << sum
                    << std::endl << "i = " << i
                    << std::endl;
           return 0;
   }
   

2. What will be the output of the following program?

   #include <iostream>
   
   using std::cout;
   using std::endl;
   
   int main()
   {
   	int i, sum;
   	for (i=10, sum=0; i>5; sum+= i--)
   	    cout << "i = " << i << endl; cout << "sum = " << sum << endl;
   }
   

3. What will be the output of the following program?

   #include <iostream>
   
   int main()
   {
   	char c1 = 'A';
   	std::cout << static_cast<char>(c1 | 0x20) << std::endl;
   	
   	char c2 = 'g';
   	std::cout << static_cast<char>(c2 ^ 0x20) << std::endl;
   
   	c1 ^= c2; 
   	c2 ^= c1;
   	c1 ^= c2;
   	std::cout << static_cast<char>(c1) << " , " 
   		<< static_cast<char>(c2) << std::endl;
   	
   	(c2 >>= 6) <<= 1;
   	c2 |= c2 << (1 << 2);
   	std::cout << static_cast<char>(c2 ^ c1) << std::endl;
   }
   

4. Show the output of the following CLR console program.
   
   #include "stdafx.h"
   
   using namespace System;
   
   int main(array<System::String ^> ^args)
   {
     int x = 120;
   
     Console::WriteLine("The value of x outside the for loop is {0}", x);
   
     for(int i = 0 ; i<3 ; i++) {
       int x = i;
       Console::WriteLine("The value of x inside the for loop is {0}", x);
     }
   
     Console::WriteLine("The value of x outside the for loop is {0}", x);
     return 0;
   }
   

5. Check whether the following program has any mistake. If yes, point out the mistakes and correct them; if no, predict the output of the program.

   // Ex2_08.cpp
   // Demonstrating variable scope
   #include <iostream>
   
   using std::cout;
   using std::endl;
   
   int count1 = 100;
   
   namespace mySpace
   { 
   	int count1 = 200;
   }
   
   namespace mySpace
   {
   	int count2 = count1 + 20;
   }
   
   int main()
   {
   	int count1 = 10;
   	cout << "local count1 = " << count1 << endl;
   	cout << "mySpace count2 = " << mySpace::count2 << endl;
   	cout << "Global count1 = " << ::count1 << endl;
   }
   

6. Consider the following program. If you input a string "Time and tide wait for no man." and press <Enter>, what will the program output?

   // Ex3_06.cpp
   // Multiple case actions
   #include <iostream>
   
   using std::cin;
   using std::cout;
   using std::endl;
   
   int main()
   { 
   	char letter = 0;
   	short vowel = 0, consonant = 0;
   	do
   	{
   		cin >> letter;
   		switch (letter*(letter >= 'a' & letter <= 'z'))
   		{
   			case 'a':
   			case 'e':
   			case 'i':
   			case 'o':
   			case 'u': vowel++;
   				break;
   			case 0: break;
   			default: consonant++;
   		}
   	} while (letter != '.');
   	cout << "The string has " 
   		<< vowel << " vowel"
   		<< (vowel>1 ? "s" : "") << " and " 
   		<< consonant << " consonant"
   		<< (consonant>1 ? "s." : ".") << endl;
   }
   

7. What will be the output of the following program?

   #include <iostream>
   
   int main()
   {
   	for (int i = 1; i < 6; i++) 
   	{
   		if (i==3)
   			continue;
   		std::cout << i << std::endl;
   	}
   }
   

8. Check whether the following program has any mistake. If yes, point out the mistakes and correct them; if no, predict the output of the program.

   // Exercising the comma operator
   #include <iostream>
   
   int main()
   {
   	short num1, num2, num3, num4;
   	num4 = ++(num1 = 10, num2 = 20, num3 = 30);
   	std::cout << num4 << std::endl;
   	return 0;
   }
   

9. Consider the program on P.147 which compute factorials. If input 10 will generate 3628800, and input 13 will generate 1932053504, what value will you get if you input 14?
10. Consider the following ISO/ANSI C++ console program:

    #include <iostream>
    #include <iomanip>
    
    using std::cout;
    using std::cin;
    using std::endl;
    using std::setw;
    
    int main()
    {
    	int N = 0;
    	int i, j;
    	do 
    	{
    		cout << "N = ? ";
    		cin >> N;
    		for (i=1; i<=N; i++)
    		{
    			int w =    (1)    ;
    			for (j=N-i; j>=0; j--)
    				cout << "*";
    			cout << setw(w);
    			for (j=N-i; j>=0; j--)
    				cout << "*";
    			cout << endl;
    		}
    
    		for (i=   (2)   ; i>0; i--)
    		{
    			int w =    (3)    ;
    			for (j=N-i; j>=0; j--)
    				cout << "*";
    			cout << setw(w);
    			for (j=N-i; j>=0; j--)
    				cout << "*";
    			cout << endl;
    		}
    	} while (N > 0);
    	return 0;
    }
    
    

    If we want to obatin the following results, what expressions should be filled into the three blanks?

    N = ? 5
    ***** *****
    ****   ****
    ***     ***
    **       **
    *         *
    **       **
    ***     ***
    ****   ****
    ***** *****
    N = ? 6
    ****** ******
    *****   *****
    ****     ****
    ***       ***
    **         **
    *           *
    **         **
    ***       ***
    ****     ****
    *****   *****
    ****** ******