Question

Let b11, b12, b13, b21, b22, b23, b31, b32, b33 represent the 3 x 3 tic tac toe board. Write a Java program that assigns each variable randomly with '_', 'O', 'X' and determines if O, X, both, or none wins. (Note that _ indicates a blank.) The program will have to display the board along with the right answer. For example, if b11='O', b12='_', b13='O', b21='X', b22='O', b23='X', b31='_', b32='X', b33='O' are generated, then it will display

Answer 1

steps:

1. Generate 0 to 2 and depending the random value assign 'O','X' or '_' to each cell.

2. There are 8 winning combinations

2.1-> 3 horizontal rows  

2.2-> 3 vertical cols

2.3-> 2 diagonal

3.if in any of the cases all symbols are equal ('O' or 'X'), then there is a winner('O' or 'X')

else

No winner

code:

//////////////////////////////////////////////////

import java.util.*;

public class HelloWorld {

static char[][] b=new char[3][3];
static int winner1=0; //flag for 'O' is winner
static int winner2=0; //flag for 'X' is winner

//this function traverse a row
//and checks all the elements are equal are not
//if all are equal it decides the winner alse returns
public static void check_row(int row_no){
char start=b[row_no][0];//this the starting element
if(start=='_')//if starting element has no symbol return
return;
for(int j=1;j<3;j++)
if(start!=b[row_no][j])//if there is a single mis match there will be no winner so return
return ;
  
//all elements are equal decide winner depending on start element
if(start=='O')
winner1=1;
else
winner2=1;

}
  
//this function traverse a Col
//and checks all the elements are equal are not
//if all are equal it decides the winner alse returns
public static void check_col(int col_no){
char start=b[0][col_no];//this the starting element
if(start=='_')//if starting element has no symbol return
return;
for(int i=1;i<3;i++)
if(start!=b[i][col_no])//if there is a single mismatch there will be no winner so return
return ;
//all elements are equal decide winner depending on start element
if(start=='O')
winner1=1;
else
winner2=1;

}
//this function traverse the first diagonal
//and checks all the elements are equal are not
//if all are equal it decides the winner alse returns
public static void check_digLR(){
char start=b[0][0];
if(start=='_')
return;
for(int i=1;i<3;i++)
if(start!=b[i][i])
return ;
if(start=='O')
winner1=1;
else
winner2=1;
  
}
//this function traverse the second diagonal
//and checks all the elements are equal are not
//if all are equal it decides the winner alse returns
public static void check_digRL(){
char start=b[0][2];
if(start=='_')
return;
for(int i=1;i<3;i++)
if(start!=b[i][2-i])
return ;
  
if(start=='O')
winner1=1;
else
winner2=1;
  
}
  
//print the board
public static void disp(){
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
System.out.print(b[i][j]+" ");
}
System.out.println();
}   
}
  
public static void main(String[] args) {

  
for(int i=0;i<3;i++)
for(int j=0;j<3;j++)
{
Random rand = new Random();
int r = rand.nextInt(3); //randomly generating the number from 0 to 2
//depending on value of r symbols are assigned to each cell
if(r==0)
b[i][j]='O';
else if(r==1)
b[i][j]='X';
else
b[i][j]='_';
}
disp();
//every possible winnig case is checked
for(int i=0;i<3;i++)
{
check_row(i);
  
check_col(i);
  
}
check_digRL();
check_digLR();
  
//Winner is displayed
if(winner1+winner2==0)
System.out.println("No winner");
else if(winner1+winner2==2)
System.out.println("Both winner");
else if(winner1==1)
System.out.println("O is Winner");
else
System.out.println("X is Winner");

}
}

///////////////////////////////////////////////////

output:

for any issues please comment down below.