写的很粗糙，就当是练练手吧

1.代码主体

define _CRT_SECURE_NO_WARNINGS 1

#include<string.h>
#include"game.h"


void menu()
{
  printf("**************************\n");
  printf("******1.play  0.exit******\n");
  printf("**************************\n");
}

void game()
{
  char ret = 0;
  //创建数组存放输出的棋盘信息
  char board[ROW][COL] = { 0 };
  //初始化棋盘
  InitBoard(board, ROW, COL);
  //打印棋盘
  DisplayBoard(board,ROW,COL);
  //互动下棋
  while (1)
  {
    //玩家下棋
    PlayerMove(board, ROW, COL);
    DisplayBoard(board, ROW, COL);
    //判断玩家是否赢
    ret =IsWin(board, ROW, COL);
    if (ret != 'C')
    {
      break;
    }
    //电脑下棋
    ComputerMove(board, ROW, COL);
    DisplayBoard(board, ROW, COL);
    //判断电脑是否赢
    ret=IsWin(board, ROW, COL);
    if (ret != 'C')
    {
      break;
    }
  }
  if (ret == '*')
  {
    printf("玩家胜利\n");
  }
  else if (ret == '#')
  {
    printf("电脑胜利\n");
  }
  else
  {
    printf("平局\n");
  }
}

void test()
{
  
  int input = 0;
  srand((unsigned int)time(NULL));
  do
  {
    menu();
    printf("请选择：");
    scanf("%d", &input);
    switch (input)
    {
    case 1:
      printf("三子棋\n");
      game();
      break;
    case 0:
      printf("结束游戏\n");
      break;
    default:
      printf("选择错误，请重新选择\n");
      break;
    }
  } 
  while (input);
}

int main()
{
  test();
  return 0;
}

2.引入的头文件

#define ROW 3//定义行为3
#define COL 3//定义列为3
#include<stdio.h>
#include<stdlib.h>
#include<time.h>


void InitBoard(char board[ROW][COL], int row, int col);//声明函数
void DisplayBoard(char board[ROW][COL], int row, int col);
void PlayerMove( char board[ROW][COL],int row,int col);
void ComputerMove(char board[ROW][COL], int row,int col);
//告诉我们四种游戏状态：
//玩家赢-‘*’
//电脑赢-‘#’
//继续-‘C’
//平局-‘Q’
char IsWin(char board[ROW][COL],int row,int col);

3.引入的函数

#define _CRT_SECURE_NO_WARNINGS 1
#include"game.h"

void InitBoard(char board[ROW][COL], int row, int col)
{
  int i = 0;
  int j = 0;
  for (i = 0; i < row; i++)
  {
    for (j = 0; j < col; j++)
    {
      board[i][j]=' ';
    }
  }
}

void DisplayBoard(char board[ROW][COL], int row, int col)
{
  int i = 0;
  for (i = 0; i < row; i++)
  {
    int j = 0;
    for (j = 0; j < col; j++)
    {
      printf(" %c ",board[i][j]);
      if (j < col - 1)
      {
        printf("|");
      }
    }
    printf("\n");
    if (i < row - 1)
    {
      for (j = 0; j < col; j++)
      {
        printf("---");
        if (j < col - 1)
        {
          printf("|");
        }
      }
    }
    printf("\n");
  }
}

void PlayerMove(char board[ROW][COL], int row, int col)
{
  int x = 0;
  int y = 0;
  //判断输入的坐标x和y的值在棋盘内
  while (1)
  {
    printf("请您落子\n");
    printf("请输入落子的坐标");
    scanf("%d%d", &x, &y);
    if ((x >= 1 && x <= row) && (y >= 1 && y <= col))
    {
      if (board[x-1][y-1]==' ')
      {
        board[x - 1][y - 1] = '*';
        break;
      }
      else
      {
        printf("已经下子过了\n");
      }
    }
    else
    {
      printf("坐标非法，请重新输入\n");
    }
  }
}

void ComputerMove(char board[ROW][COL],int row,int col)
{
  int x = 0;
  int y = 0;
  printf("电脑落子\n");
  while (1)
  {
    x = rand() % 3;
    y = rand() % 3;
    if (board[x][y] == ' ')
    {
      board[x][y] = '#';
      break;
    }
  }

}

int IsFull(char board[ROW][COL], int row, int col)
{
  int i = 0;
  int j = 0;
  for (i = 0; i < row; i++)
  {
    for (j = 0; j < col; j++)
    {
      if (board[i][j] == ' ')
      {
        return 0;//棋盘没落满了子
      }
    }
  }
  return 1;//棋盘落满子
}

char IsWin(char board[ROW][COL], int row, int col)
{
  int i = 0;
  //横三列
  for (i = 0; i < row; i++)
  {
    if ((board[i][0] == board[i][1] && board[i][1] == board[i][2]) && (board[i][0] != ' '))
    {
      return board[i][0];
    }
  }
  //竖三行
  for (i = 0; i < col; i++)
  {
    if ((board[0][i] == board[1][i] && board[1][i] == board[2][i]) && (board[0][i] != ' '))
    {
      return board[0][i];
    }
  }
  //对角线
  if ((board[0][0] == board[1][1]) && (board[1][1] == board[2][2]) && (board[0][0] != ' '))
  {
    return board[0][0];
  }
  if ((board[2][0] == board[1][1]) && (board[1][1] == board[0][2]) && (board[2][0] != ' '))
  {
    return board[2][0];
  }
  //判断是否平局
  if (1 == IsFull(board, ROW,COL))
  {
    return 'Q';
  }
  return 'C';