C++ realizes tic tac toe game

This article is an example of C++ to share the implementation of tic-tac-toe game specific code for your reference, the specific content is as follows

Initial implementation of double player input, operation of the game.
The next step is to implement the man-machine game.

#include<iostream>
using namespace std;

void Player1(void);  // The player 1 The input ( operation ) function 
void Player2(void);  // The player 2 The input ( operation ) function 
void game_judge(void); // Winning or losing judgment 
void game_start(void); // The game start 

int rows = 3,cols = 3; // The board size 

bool win1_flag = false; // The player 1 Winning marker 
bool win2_flag = false; // The player 2 Winning marker 
char pieces[3][3] = {{' ',' ',' '},
      {' ',' ',' '},
      {' ',' ',' '}};;  // Initialize the 

void draw(void)  // Print out the checkerboard 
{
 for(int i=0;i<rows;i++){
  for(int j=0;j<cols;j++){
   cout<<pieces[i][j];
   if(j< cols-1)
    cout<<" | ";
  }
  cout<<"\n";
  if (i<rows-1)
   cout <<" -- -- -- -- -- "<<endl;
 }
 cout <<"\n";
}

void game_start(void) // The game start 
{
 int n=0;   // The total 3*3=9 Input a , Used to determine whether or not to fill out 
 bool flag = false;  // The player switches flag bits 
 cout << " The game start "<<endl; 
 while(n<9 & win1_flag == false & win2_flag == false) // Missing out , Not a winner to draw, then continue the game 
 {
  if(flag == false){    // Switch to the player 1
   cout << " The player 1 The input :"<<endl;
   Player1();     // The player 1 Input chess position 
   flag = true;    // Under the 1 Step is the player 2
  }
  else{        // Switch to the player 2
   cout << " The player 2 The input :"<<endl;
   Player2();     // The player 2 Input chess position 
   flag = false;    // Under the 1 Step is the player 1 
  }
  game_judge();  // Determine the outcome 
  draw();   // Print out the checkerboard 
  n++;    // The chessboard was added again 1 pawn 
 }
}

void game_judge(void)  // Determine the outcome 
{
 for(int i=0;i<rows;i++){ 
  if(pieces[i][0] == pieces[i][1]& pieces[i][0] == pieces[i][2] & pieces[i][0] != ' ') // Judge horizontal direction full 3 Same piece 
  {
   if(pieces[i][0] == 'O')  // It's the player 1 The chessmen are still players 2
    win1_flag = true;  // The player 1 win 
   else
    win2_flag = true;  // The player 2 win 
  }
  if(pieces[0][i] == pieces[1][i]& pieces[1][i] == pieces[2][i] & pieces[0][i] != ' ') // Judge vertical direction full 3 Same piece 
  {
   if(pieces[0][i] == 'O')  // It's the player 1 The chessmen are still players 2
    win1_flag = true;  
   else
    win2_flag = true;
  }
  if((pieces[0][0] == pieces[1][1]& pieces[1][1] == pieces[2][2] & pieces[0][0] != ' ') // Judge oblique direction full 3 Same piece 
   |(pieces[0][2] == pieces[1][1]& pieces[1][1] == pieces[2][0] & pieces[2][0] != ' '))
  {
   if(pieces[1][1] == 'O')  // It's the player 1 The chessmen are still players 2
    win1_flag = true;
   else
    win2_flag = true;
  }
 }
}


void Player1(void)
{
 int row0,col0;
 cin>>row0>>col0; // The player 1 The input position 
 while(pieces[row0-1][col0-1] != ' ') // Determines if the position has a chess piece , Or there is no 
 {
  cout<<" Incorrect input for this position , Please re-enter "<<endl;
  cout<<" Please enter the number of rows and columns (1-3), Space off :";
  cin >>row0>>col0; // Reenter position 
 }
 pieces[row0-1][col0-1] = 'O'; // Place players on the board 1 pieces 
}

void Player2(void)
{
 int row1,col1;
 cin>>row1>>col1; // The player 1 The input position 
 while(pieces[row1-1][col1-1] != ' ') // Determines if the position has a chess piece , Or there is no 
 {
  cout<<" Incorrect input for this position , Please re-enter "<<endl;
  cout<<" Please enter the number of rows and columns (1-3), Space off :";
  cin >>row1>>col1; // Reenter position 
 }
 pieces[row1-1][col1-1] = 'X'; // Place players on the board 2 pieces 
}


int main(int argc,char** argv)
{ 
 
 cout<<" In-game loading "<<endl;
 draw();   // Print initial checkerboard 
 game_start(); // Start the game 
 if(win1_flag == true)  // The player 1 win 
  cout<<" The player 1 win !"<<endl;
 if(win2_flag == true)  // The player 2 win 
  cout<<" The player 2 win !"<<endl;
 if(win1_flag == win2_flag) // Did not win , A draw 
  cout<<" A draw !"<<endl;

 return 0;
}