arrays - Stop Tic Tac Toe from overwriting moves in C -

sorry guys asked question couple of hours ago last thing need finish project. program allows overwrite of moves. if player 1 picks first square, allow player 2 pick square. else functions have been failing @ implementation of this.

any ideas? put 1 part of code since lot of code sadly copy , pasted. i'm new, haven't figured out optimization yet , out of time project appreciated.

so in code included printing of original board , first move of first player (if playing 2 humans). should enough if wants see rest of code please let me know have left out of it. thanks!!!

#include <stdio.h> #include <stdlib.h>  /* known bugs: allows players place 1 or 2 on board if there 1 or 2 in spot. */  int main() {     char board[3][3];     int i,j,k,l, player, move;      for(i=0;i<=3;i++) // prints initial board of 0's     {         for(j=0;j<=3;j++)         {             board[i][j] = '0';         }     }       printf("hello! want play alone or computer? \n\n"            "enter 1 alone or 2 play friend!\n");     scanf("%d", &player);      if (player == 2)     {         for(k=0;k<9;k++) // 9 moves max.         {             printf("\n\n"); // print board again.             printf(" %c | %c | %c\n", board[0][0], board[0][1], board[0][2]);             printf("---+---+---\n");             printf(" %c | %c | %c\n", board[1][0], board[1][1], board[1][2]);             printf("---+---+---\n");             printf(" %c | %c | %c\n", board[2][0], board[2][1], board[2][2]);                          {                 printf("player 1, move? enter 1-9\n");                 scanf("%d", &move);                  if (move == 1)                     board[0][0] = '1';                 if (move == 2)                     board[0][1] = '1';                 if (move == 3)                     board[0][2] = '1';                 if (move == 4)                     board[1][0] = '1';                 if (move == 5)                     board[1][1] = '1';                 if (move == 6)                     board[1][2] = '1';                 if (move == 7)                     board[2][0] = '1';                 if (move == 8)                     board[2][1] = '1';                 if (move == 9)                     board[2][2] = '1';              }while(move>9 && move <1); 

1. i suggest using switch case in last while loop (see example)
2. i think need check if field referencing taken!

** check()**

void check (char *c, int *move){     if(*c == '0'){         *c = '1';     }else {         printf("\nthis field taken! please choose one.\n");         /* since repeat long move bigger 9 or smaller            1, have user make choice. */         *move = 0;      } } 

** last while**

do {     printf("player 1, move? enter 1-9\n");     scanf("%d", &move);      switch (move){         case 1:             check(&board[0][0], &move);             break;         case 2:             check(&board[0][1], &move);             break;         case 3:             check(&board[0][2], &move);             break;         case 4:             check(&board[1][0], &move);             break;         case 5:             check(&board[1][1], &move);             break;         case 6:             check(&board[1][2], &move);             break;         case 7:             check(&board[2][0], &move);             break;         case 8:             check(&board[2][1], &move);             break;         case 9:             check(&board[2][2], &move);             break;         default:             printf("\nerror! choose field between 1 , 9\n");     }  }while(move>9 || move <1); 

note: others said, for-loops need iterate until i/j < 3, since array has size of 3 (indexes 0, 1, 2);

note 2: while statement must move > 9 or move < 1 since int can't bigger 9 , smaller 1 @ same time, cause infinite loop.