HW21
COP-3223H

See HW7's Setup for how to prepare for performing and submitting your homework.

1. (hw21-1.c) Write a program that replace each value with its square in a 3x5 matrix, then prints it out. You can use the following skeleton code:

   #include <stdio.h>
   #include <unistd.h>
   
   int main(int argc, char **argv) {
     int a[3][5] = { {1, 2, 3, 4, 5}, {6, 7, 8, 9, 10}, {11, 12, 13, 14, 15} };
     int width = 3;
     int height = 5;
   
     // add your implementation here
   
     return 0;
   }
   

2. (hw21-2.c) Rewrite the tic-tac-toe program in class to use a multidimensional (3x3) array instead of a single 9-element array. Below is the single array version.

   #include <stdio.h>
   #include <assert.h>
   
   int main(int argc, char **argv) {
     char c = '\0';
   
     char board[] = { '1', '2', '3', '4', '5', '6', '7', '8', '9' };
     int boardlen = 9;
   
     // turn 0 is x, turn 1 is o.
     int turn = 0;
     while (1) {
       printf("\x1b[2J");
       printf("\x1b[H");
       for (int i = 0; i < boardlen; i++) {
         putchar(board[i]);
         if ((i % 3) == 2) {
           putchar('\n');
         }
       }
       printf("last turn: %c\n", c);
       switch (turn) {
       case 0:
         printf("X's turn\n");
         break;
       case 1:
         printf("O's turn\n");
         break;
       default:
         assert(0);
       }
       scanf("%c", &c);
       int index = - 1;
   
       switch (c) {
       case '1':
         index = 0;
         break;
       case '2':
         index = 1;
         break;
       case '3':
         index = 2;
         break;
       case '4':
         index = 3;
         break;
       case '5':
         index = 4;
         break;
       case '6':
         index = 5;
         break;
       case '7':
         index = 6;
         break;
       case '8':
         index = 7;
         break;
       case '9':
         index = 8;
         break;
       default:
         index = -1;
         break;
       }
   
       if (0 <= index && index < 9 && !('X' == board[index] || 'O' == board[index])) {
         switch (turn) {
         case 0:
           board[index] = 'X';
           turn = 1;
           break;
         case 1:
           board[index] = 'O';
           turn = 0;
           break;
         default:
           assert(0);
           break;
         }
       }
     }
   }
   

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See HW7's Self-check for instructions on checking what you have submitted to the remote grading repository.