问题
I am so confused. I am trying to create a tic tac toe game using windows c++ visual. So far I was doing good until I kept getting errors. I tried looking for help but none of the answers seemed right. This is my practice problem.
- Implement displayBoard to display Tic Tac Toe board.
Prompt User for a box on the board to select, i.e. a number between 1 and 9 with 1 being the upper left corner.
use cin.get(box) to get the box number and isdigit to verify it is a number; 1 | 2 | 3 4 | 5 | 6 7 | 8 | 9 If the box is available put the appropriate X or O in there and switch players, i.e. X becomes O and vice versa. If the box is NOT available warn the user and get another box until they select a valid open box.
After all spots have been select Display "Game Over!";
- Write a main function to use the TicTacToe class and test all of the above functionality.
.
#include<iostream>
using namespace std;
class TicTacToe {
public:
void displayBoard();
void getMove();
void playGame();
private:
char board[9];
char player; // Switch after each move.
};
int main ()
{
TicTacToe ttt;
// you need to do the following in a loop 9 times
ttt.playGame();
}
void TicTacToe::playGame()
{
getMove();
// Your implementation here...
}
void TicTacToe::displayBoard()
{
// Your implementation here...
}
void TicTacToe::getMove()
{
cout << "Enter Box: ";
char c;
cin.get(c);
if (c > '9' || c < '0')
// Error message here.
int number = c - '0';
cout << "your number is " << number;
// Your implementation here...
}
回答1:
you need a statement to go after the if
even if its just a ;
but maybe you want
if (c > '9' || c < '0')
cout << "Not a Number!";
回答2:
Ok, so the issue here is the "if" statement. The problem is that you haven't closed the if statement. So what the compiler sees is
cout << "Enter box: ";
char c;
cin.get(c);
if(c > '9' || c < '0')
{
//Compiler thinks that it should only convert the character
//to a number if you got the *wrong* number
int number = c - '0';
}
//the integer number when out of scope in the if statement. So now it doesn't exist
//which means you will get a "variable not declared" error
cout << "your number is " << number;
When you create an if statement and you don't put braces around the block of code it should execute, then the next line after the if statement becomes the conditional statement. What you need to do is close the if statement. simply adding a semicolon is sufficient:
if (c > '9' || c < '0');
but it means you don't handle the error, which is pretty bad, so at least put an error message in the if statement to tell the user that they've made a mistake.
回答3:
//Play Tic Tac Toe game between user and computer
#include<iostream>
#include<cstdio>
#include<stdlib.h>
#include<time.h>
using namespace std;
char BLANK='B';
/***************** Display the Matrix **********************************************/
//Display the matrix
void display(char matrix[3][3])
{
for(int i=0;i<3;i++){
for(int j=0;j<3;j++)
cout<<matrix[i][j]<<"\t";
cout<<endl;
}
}
/************** Chance of WIN Function *****************************************************/
//Funtion to detect the chance of either for user or systemĵ
int chance_of_win(char matrix[3][3],int i, int j,char choice){
int result=0;//This variale is used to return the required position
char other_choice;//This variable is used for other choice of the variable choice
if(choice=='o')
other_choice='x';
else
other_choice='o';
int count1=0;//This variable is used to check the count upto 2
//Diagonal Intelligent
if(i==j){
for(int k=0;k<3;k++){
if(matrix[k][k]==choice)
count1++;
if(count1==2){ // That means user is going to win and system has to stop that
for(int k=0;k<3;k++){
if(matrix[k][k]!=choice && matrix[k][k]!=other_choice){
int temp=k;
temp=temp*10;
result=temp+k;
return result;
}
}
}
}//for looop ends here
}//If Structure ends here
count1=0; //Reinitilize the count to zero
//Reverse Diagonal intelligent
for(int m=0,n=2;m<3,n>=0;m++,n--){
if(matrix[m][n]==choice){
count1++;
}
if(count1==2){ // That means user/system is going to win reverse diagnally
for(int m=0,n=2;m<3,n>=0;m++,n--){
if(matrix[m][n]!=choice && matrix[m][n]!=other_choice){
int temp=m;
temp=temp*10;
result=temp+n;
return result;
}
}
}//End of If structure
}//End for loop
count1=0; //Reinitilize the count to zero
//Row Intelligent
for(int k=0;k<3;k++){
if(matrix[i][k]==choice)
count1++;
if(count1==2){ // That means user/system is going to win
for(int k=0;k<3;k++){
if(matrix[i][k]!=choice && matrix[i][k]!=other_choice){
int temp=i;
temp=temp*10;//for the ith coordiante
result=temp+k;//for the jth cordinate
return result;//Return the required attribute of i and j
}
}
}
}//for looop ends here
count1=0; //Reinitilize the count to zero
//Column Intelligent
for(int k=0;k<3;k++){
if(matrix[k][j]==choice)
count1++;
if(count1==2){ // That means user is going to win and system has to stop that
for(int k=0;k<3;k++){
if(matrix[k][j]!=choice && matrix[k][j]!=other_choice){
int temp=k;
temp=temp*10;//for the ith coordinate
result=temp+j;//for the jth coordinate
return result;//Return the required attribute of i and j
}
}
}
}//for looop ends here
return result;
}//function ends here
/******************* Check Win Bool Function ******************************************************/
//This function is used to check the win of the system/user
bool checkwin(char matrix[3][3],int i, int j,char choice){
bool flag=false;//Initialize the chance of win false
int count1=0;
//Diagonal checkwin forward
if(i==j){
for(int k=0;k<3;k++){
if(matrix[k][k]==choice){
count1++;
}
if(matrix[k][k]==BLANK)
break;
}
if(count1==3)//Means all diagonal elements are equal
flag=true;
}
//If the Diaganoal Forward is same then return
if(flag){
cout<<"Diagonal Win\n";
return flag;
}
//Reverse Diagonal checkwin
for(int m=0,n=2;m<3,n>=0;m++,n--){
if(matrix[m][n]!=choice || matrix[m][n]==BLANK){
flag=false;//If diagonal is not same
break;
}
flag=true;
}
//If the Reverse Diaganoal Forward is same then return
if(flag){
cout<<"Reverse Diagonal Win\n";
return flag;
}
//Row checkwin
for(int k=0;k<3;k++){
if(matrix[i][k]!=choice || matrix[i][k]==BLANK){
flag=false;// Row is not same
break;
}
flag=true;
}
//If row is same then return
if(flag){
cout<<"Row Win\n";
return flag;
}
//Column checkwin
for(int k=0;k<3;k++){
if(matrix[k][j]!=choice || matrix[k][j]==BLANK){
flag=false;//Column is not same
break;
}
flag=true;
}
//If the Column is same then return
if(flag){
cout<<"Column Win\n";
return flag;
}
return flag;//return the result false result i.e there is no chance of win
//as we have checked all the conditions
}
/************************* Main Function **************************************************/
int main(){
char matrix[3][3];
bool flag;
int toss;
srand(time(NULL));
toss=rand()%2;
if(toss){
flag=true;
cout<<"User Wins the Toss\n";
}
else{
flag=false;
cout<<"System Wins the Toss\n";
}
//Initialise all the elements of matrix to BLANK i.e. Blank
for(int i=0;i<3;i++)
for(int j=0;j<3;j++)
matrix[i][j]=BLANK;
cout<<"For user the choice is o\n";
cout<<"For system the choice is x\n";
int v=1;//Initialise the the variable v , it has the increment till 9 to cover all the elements of the matrix
bool system1=false;//To check the chance of win of system
int user_status=0;//To check the chance of win of user and accordingly system will put his move
int system_status;////To check the chance of win of system and accordingly system will put his move
while(v<=9){
int i,j;// "i" is for the row coordinate and "j" is for the column coordinate
if(flag==true){// If user win's the toss
cout<<"Yours turn\n";
cout<<"Enter the row coordinate";
cin>>i;
i--;//For user convenience i th coordinate
cout<<"Enter the column coordinate";
cin>>j;
j--;//For user convenience jth coordinate
if(matrix[i][j]==BLANK)
matrix[i][j]='o';//Put the user move
else{
cout<<"Already Occupied\n"; //Warn user to fill the blank space
continue;//Don't count this in "variable v" means don't increment the variable "v"
//as it was invalid move
}
// After three attempts it will check , this code is for system
if(v>2)
user_status=chance_of_win(matrix,i,j,'o');//User chance of win
//checkwin whether game is over i.e whether user win
if(v>4){
if(checkwin(matrix,i,j,'o')){
cout<<"\n\tBingo !! User win\n\tCongrats Well played\n";
display(matrix);
return 0;
}
}
flag=false;// Let the System play next move
display(matrix);//display the matrix
cout<<"\nWait! System turns\n";
}
else{//System's Turn
if(system1==true){//Chance of System of winning
j=system_status%10;//get the j coordinate
i=system_status/10;//get the i coordinate
//cout<<"System chance win i = "<<i<<" j = "<<j<<endl;
/*If Structure of Check whether place is empty for winning the system*/
if(matrix[i][j]==BLANK){//Is place is empty
matrix[i][j]='x';
if(checkwin(matrix,i,j,'x')){
display(matrix);//Display the current scenerio of the game
cout<<"Sorry You loose !! System wins\n";
return 0;
}//end if structure of check win
}
else//Means space is occupied by user, and chance of winning by system is lost
system1=false;//Now let the system to defense the user's move
/*Ends If Structure of Check whether place is empty for winning the system*/
}
if(system1==false){
if(user_status!=0){//If User is going to win , warn the system
j=user_status%10;//get the j coordinate
i=user_status/10;//get the i coordinate
//cout<<"User chance win i = "<<i<<" j = "<<j<<endl;
}
else{
if(v==9){//There is no point to check random number if noone is winning at the end
cout<<"\t\tMatch draw"<<endl;
return 0;
}
srand(time(NULL));
i=rand()%3; //random i coordinate
srand(time(NULL));
j=rand()%3; //random j coordinate
}
/*If System turn's of writting*/
if(matrix[i][j]==BLANK)
matrix[i][j]='x';
else
continue;
/*End If Structure of writting system turn's*/
}//end If Structure is sytem chance of win = false
if(v>2){// This condition is necessary to avoid irrevelant check
system_status=chance_of_win(matrix,i,j,'x'); //System chance of win
if(system_status==0){
system1=false;
cout<<"\n Not System Chance of win \n";
}
else{
system1=true;
cout<<"\n System Chance of win \n";
}
}
else{
system_status=0;
system1=false;
}
flag=true;//Let the user play his next move
display(matrix);
}
v++;
}//end of while v<9
return 0;
来源：https://stackoverflow.com/questions/6825686/c-tic-tac-toe-game