2-2
==========
#include <stdio.h>

#define MAX_STRING_LENGTH 100

int main(void)
{
	/*
	for (i = 0; i < lim-1 && (c=getchar()) != '\n' && c != EOF; ++i)
		s[i] = c;
	*/

	int i = 0,
		lim = MAX_STRING_LENGTH,
		c;
	char s[MAX_STRING_LENGTH];

	while (i < (lim - 1))
	{
		c = getchar();

		if (c == EOF)
			break;
		else if (c == '\n')
			break;

		s[i++] = c;
	}

	s[i] = '\0';   /* terminate the string */

	return 0;
}


2-3
==========
#include <stdio.h>
#include <math.h>

int upperToLower(int character);

int main(void){
        char hexString[10];
        int i, j, c, input, integer;

        char hexadecimals[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
                '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};

        i = 0;
        while ((c = getchar()) != EOF)
        {
                if (c >= 'A' & c <= 'Z')
                {
                        c = upperToLower(c);
                }
                hexString[i] = c;
                ++i;
        }
        hexString[i] = '\0';

        integer = 0;
        for (j = i - 1; j >= 0; --j)
        {
                if(hexString[j] >= 'a' && hexString[j] <= 'z')
                        {

                                for(int k = 0; k < 16; ++k)
                                {
                                        if(hexString[j] == hexadecimals[k])
                                        {
                                                integer = integer + k * pow(16, i-1-j);
                                        }
                                }
                        }
                else
                        integer = integer + (hexString[j] - '0') * pow(16, i-1-j);
        }

        printf("\nThe integer value of the hexadecimal string %s is ", hexString);
        printf("d.\n", integer);
}

int upperToLower(int input){
        int lower;

        lower = input + 'a' - 'A';

        return lower;
}


2-4
==========









2-5
==========
int any(char s1[], char s2[])
{
  int i;
  int j;
  int pos;

  pos = -1;

  for(i = 0; pos == -1 && s1[i] != '\0'; i++)
  {
    for(j = 0; pos == -1 && s2[j] != '\0'; j++)
    {
      if(s2[j] == s1[i])
      {
        pos = i;
      }
    }
  }

  return pos;
}


2-6
==========


2-7
==========

2-8
==========

2-9
==========
int bitcount(unsigned x)	{
	int b=0;
	while (x != 0)	{
		x &= (x-1);
		b++;
	}

	return b;
}

int main()	{
	printf("%d\n", bitcount(25));
}


2-10
==========
#include <stdio.h>

int lower(int c)	{
	return (c >= 'A' && c <= 'Z') ? c + 'a' - 'A' : c;
}


3-1
==========
int binsearch2(int x, int v[], int n)
{
  int low, high, mid;

  low = -1;
  high = n;
  while (low + 1 < high) {
    mid = (low + high) / 2;
    if (v[mid] < x)
      low = mid;
    else
      high = mid;
  }
  if (high == n || v[high] != x)
    return -1;
  else
    return high;
}



3-2
==========
void escape(char * s, char * t) {
    int i, j;
    i = j = 0;

    while ( t[i] ) {

        /*  Translate the special character, if we have one  */

        switch( t[i] ) {
        case '\n':
            s[j++] = '\\';
            s[j] = 'n';
            break;

        case '\t':
            s[j++] = '\\';
            s[j] = 't';
            break;

        case '\a':
            s[j++] = '\\';
            s[j] = 'a';
            break;

        case '\b':
            s[j++] = '\\';
            s[j] = 'b';
            break;

        case '\f':
            s[j++] = '\\';
            s[j] = 'f';
            break;

        case '\r':
            s[j++] = '\\';
            s[j] = 'r';
            break;

        case '\v':
            s[j++] = '\\';
            s[j] = 'v';
            break;

        case '\\':
            s[j++] = '\\';
            s[j] = '\\';
            break;

        case '\"':
            s[j++] = '\\';
            s[j] = '\"';
            break;

        default:

            /*  This is not a special character, so just copy it  */

            s[j] = t[i];
            break;
        }
        ++i;
        ++j;
    }
    s[j] = t[i];    /*  Don't forget the null character  */
}