PROBLEM 1.
runner% cat final1.c	/* another solution */
#include <stdio.h>	#include <stdio.h>

void main(void)	void main(void)
{	{
   int i = 0, n;	   int n;
   scanf("%i", &n);	   scanf("%i", &n);
   for (i = n-1; i >= 0; i--)	   while (n > 0)
      printf("%i ", i);	      printf("%i ", i);
   printf("\n");	   printf("\n");
} 	}
coyote19% cc -o final1 final1.c
coyote19% final1
5
4 3 2 1 0
runner%

PROBLEM 2.
#include <stdio.h>
void main(void)
{
   int i;
   double arr[200];
   int zero_found;
   for (i = 0; i < 100; i++)
      arr[i] = (double)(i+1);
   /* search for zero */
   zero_found = 0;
   for (i = 0; i < 100; i++) {
      if (arr[i] == 0.0) zero_found = 1;
      break;   /* works without the break */
   }
   if (zero_found) printf("Zero found\n");
   else printf("No zeros\n");
}

PROBLEM 3.
#include <stdio.h>
#include <ctype.h>
void main(void)
{
   char ch;
   int digits = 0;
   while( (ch = getchar()) != EOF)
      if (isdigit(ch)) digits++;
   printf("Number of digits: %i\n", digits);
}
runner% cc -o final_1 final_1.c
runner% final_1 < final_1.c
Number of digits: 1

PROBLEM 4.
runner% cat final3.c
#include <stdio.h>
#define MAXFIB 40

void main(void)
{
   int f[MAXFIB];
   int i;
   f[0] = 0; f[1] = 1;
   for (i = 2; i < MAXFIB; i++)
      f[i] = f[i-1] + f[i-2];
   for (i = 0; i < MAXFIB; i++)
      printf("Fibonacci number %2i = %8i\n",
         i, f[i]);
}

runner% cc -o final3 final3.c
runner% final3
Fibonacci number  0 =        0
Fibonacci number  1 =        1
Fibonacci number  2 =        1
Fibonacci number  3 =        2
Fibonacci number  4 =        3
Fibonacci number  5 =        5
 ...  (lines missing)
Fibonacci number 38 = 39088169
Fibonacci number 39 = 63245986

PROBLEM 5. Carnivals love this game because they make an average of 7.87 cents for 
each dollar that players bet.  The players ("suckers") sometimes reason as follows: 
there are 3 chances out of 6 that my number will come up, so I should come out even 
that way, and the extra paid off for duplicates is just gravey. 
/* Simulate game of Chuck-O-Luck 
 * Each time, read in a number to bet on: bet_on, 1 <= bet_on <= 6
 * Simulate rolling three dice, results in: d[0], d[1], d[2]
 * Count number of dice matching your number: num_dice
 * If num_dice > 0, you win num_dice dollars, but if
 *    num_dice == 0, you lose a dollar.
 * Program written by N. Wagner, April 29, 1998
 */
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define MAX_GAMES 100000       /* total number of games to play        */
int roll(void);                /* single roll of a die                 */
void main(void)
{
   int bet_on = 4;             /* the number you are betting on        */
   int winnings = 0;           /* total winnings for all games         */
   int win[4] = {0, 0, 0, 0};  /* keep track of the number of times the*/
                               /*   dice rolled matched your number    */
   int n;                      /* count the games                      */
   int i;                      /* counter used for dice                */
   int num_dice;               /* number of dice matching your number  */
   int d[3];                   /* results of three rolls               */
   srand48((long)time(NULL));  /* initialize random number generator   */
   for (n = 0; n < MAX_GAMES; n++) { /* play MAX_GAMES number of games */
      d[0] = roll(); d[1] = roll(); d[2] = roll();   /* three rolls    */
                         /* count number of rolls matching your number */
      num_dice = 0;
      for (i = 0; i < 3; i++)
         if(d[i] == bet_on) num_dice++;
      win[num_dice]++;         /* keep track of each value of num_dice */
      if (num_dice == 3)      winnings +=  3;   /* add to winnings     */
      else if (num_dice == 2) winnings +=  2;   /* add to winnings     */
      else if (num_dice == 1) winnings +=  1;   /* add to winnings     */
      else if (num_dice == 0) winnings += -1;   /* take from winnings  */
   }
   printf("Total winnings:%i dollars, or %.3f%%", winnings,
      100.0*winnings/MAX_GAMES);
   printf(", out of %i bet total\n", MAX_GAMES);
   printf("Percentages:  3: %.5f%%, 2: %.5f%%, 1: %.5f%%, 0: %.5f%%\n",
       win[3]*100.0/MAX_GAMES,win[2]*100.0/MAX_GAMES,
       win[1]*100.0/MAX_GAMES,win[0]*100.0/MAX_GAMES);
   printf("Exact values: 3: %.5f%%, 2: %.5f%%, 1: %.5f%%, 0: %.5f%%\n",
       1.0*100.0/216.0, 15.0*100.0/216.0,
       75.0*100.0/216.0, 125.0*100.0/216.0);
}
int roll(void)
{
   return (int)(6.0*drand48() + 1.0);
}
runner% final  (with MAX_GAMES equal to 100000000)
Total winnings:-7855374 dollars, or -7.855%, out of 100000000 bet total
Percentages:  3: 0.46376%, 2: 6.94421%, 1: 34.72848%, 0: 57.86355%
Exact values: 3: 0.46296%, 2: 6.94444%, 1: 34.72222%, 0: 57.87037%
Notice that you are losing nearly 8% of the money you bet. (7.87% on the average.)
If we make the one change that the game pays $20 in case of all three dice are equal 
to your number, then the game is exactly fair.
runner% final  (with MAX_GAMES equal to 100000000 and one line of
   code changed:  if (num_dice == 3) winnings +=  3;
   changed to:    if (num_dice == 3) winnings += 20;)
Total winnings:3990 dollars, or 0.004%, out of 100000000 bet total
Percentages:  3: 0.46306%, 2: 6.94374%, 1: 34.72425%, 0: 57.86894%
Exact values: 3: 0.46296%, 2: 6.94444%, 1: 34.72222%, 0: 57.87037%