1.



#include <iostream.h>
#include <string.h>

int main(int argc, char **argv) {
  int i;
  char *word;
  int err;

  for (i = 1; i < argc; i++) {
        err=0;
        word = argv[i];
        switch (word[0]) {
        case 'h':
        case 'H':
                if (strcmp(word+1, "ello")==0)
		        cout << "Hello, I'm pleased to meet you!" << endl;
                else err=1;
                break;
        case 'g':
        case 'G':
                if (strcmp(word+1, "oodbye")==0)                       
		   cout << "Goodbye.  I've enjoyed talking with you." << endl;
                else err=1;
                break;
        case 'b':
        case 'B':
                if (strcmp(word+1, "usy")==0)
                        cout << "Are you working or playing?" << endl;
                else err=1;
                break;
        case 'p': 
        case 'P':
                if (strcmp(word+1, "ause")==0)
                        cout << "I'm glad you were able to take a bit of time off from working so hard." << endl;
                else err=1;
                break;
        case 'w':
        case 'W':
                if (strcmp(word+1, "ork")==0)
                        cout << "Too bad you can't be outside today.  It's a beautiful day." << endl;
                else err=1;
                break;
        default:
                err=1;
        }
        if (err==1)
                cout << "I'm sorry, I don't understand what you said." << endl;
  }
}









2.


(a) Semicolon after "if" statement should be dropped


(b) total should be initialized


(c) The version of the question you had was valid; the actual question on the book was:

while(y>0) {
	cout << y << endl;
	++y;
}

...which will loop endlessly if y is positive in the first place. As a result, the test should be:

while (y < 0)




3.

i=0;
while (i<max_lenth)
{
        if (input_line[i] == '?') quest_count++;
        i++;
}



4.

#include <iostream.h>

int strlen(const char *);

char *strcpy( char *, const char *);

int strcmp( const char *, const char *);

int main(int argc, char **argv)
{
        char string1[]="hello world!";
        cout <<"String 1 is: " <<string1 <<endl;
        cout <<"The length of String 1 is: " << strlen ( string1 ) << endl;
        char string2[strlen(string1)+2];
        cout << "Copy String 1 into String 2, the result is: ";
        cout << strcpy( string2, string1) << endl;
        cout << "Compare String 1 and String 2, the result is: " << strcmp( string2, string1) << endl;
        cout << "Compare \"hello1\" and \"hello2\", the result is: " << strcmp( "hello1", "hello2") << endl;
        return 0;
}




char *strcpy( char *target, const char *source)
{
        char *answer;
        answer=target;
        while (*source!='\0')
        {
                *target=*source;
                target++;
                source++;
        }
        *target='\0';
        return answer;
}




int strcmp ( const char *str1, const char *str2)
{
        while (*str1!='\0')
                {
                        if (*str1!=*str2) return *str1-*str2;
                        str1++;
                        str2++;
                }
        return *str1-*str2;
}





int strlen (const char *s)
{
        int answer=0;
        for (;*s!='\0' ;s++ )
        {
                answer++;
        }
        return answer;
}