Thread: Boolean Value cross-functional in Game TicTacToe

Try compiling at the maximum warning level (-Wall option for gcc, else consult your compiler docs):

Code:

$ make foo
gcc -Wall -ggdb3 -pedantic -std=gnu99 -O0 -o foo foo.c -lm -lpthread -lrt
foo.c:18:3: warning: ISO C forbids empty initializer braces [-Wpedantic]
   {},
   ^
foo.c:19:3: warning: ISO C forbids empty initializer braces [-Wpedantic]
   {}
   ^
foo.c: In function ‘naechsterZug’:
foo.c:85:5: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘char (*)[100]’ [-Wformat=]
     scanf("%s", &eingabe);
     ^
foo.c: In function ‘pruefeGewinn’:
foo.c:101:710: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
   if (((spielfeld[0][0] == kreuz) && (spielfeld[0][1] == kreuz) && (spielfeld[0][2] == kreuz)) || ((spielfeld[1][0] == kreuz) && (spielfeld[1][1] == kreuz) && (spielfeld[1][2] == kreuz)) || ((spielfeld[2][0] == kreuz) && (spielfeld[2][1] == kreuz) && (spielfeld[2][2] == kreuz)) || ((spielfeld[0][0] == kreuz) && (spielfeld[1][0] == kreuz) && (spielfeld[2][0] == kreuz)) || ((spielfeld[0][1] == kreuz) && (spielfeld[1][1] == kreuz) && (spielfeld[2][1] == kreuz)) || ((spielfeld[0][2] == kreuz) && (spielfeld[1][2] == kreuz) && (spielfeld[2][2] == kreuz)) || ((spielfeld[0][0] == kreuz) && (spielfeld[1][1] == kreuz) && (spielfeld[2][2] == kreuz)) || ((spielfeld[0][2] == kreuz) && (spielfeld[1][1] == kreuz)) && (spielfeld[2][0] == kreuz)) {
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      ^
foo.c:107:712: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
     if (((spielfeld[0][0] == kreis) && (spielfeld[0][1] == kreis) && (spielfeld[0][2] == kreis)) || ((spielfeld[1][0] == kreis) && (spielfeld[1][1] == kreis) && (spielfeld[1][2] == kreis)) || ((spielfeld[2][0] == kreis) && (spielfeld[2][1] == kreis) && (spielfeld[2][2] == kreis)) || ((spielfeld[0][0] == kreis) && (spielfeld[1][0] == kreis) && (spielfeld[2][0] == kreis)) || ((spielfeld[0][1] == kreis) && (spielfeld[1][1] == kreis) && (spielfeld[2][1] == kreis)) || ((spielfeld[0][2] == kreis) && (spielfeld[1][2] == kreis) && (spielfeld[2][2] == kreis)) || ((spielfeld[0][0] == kreis) && (spielfeld[1][1] == kreis) && (spielfeld[2][2] == kreis)) || ((spielfeld[0][2] == kreis) && (spielfeld[1][1] == kreis)) && (spielfeld[2][0] == kreis)) {
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        ^
foo.c: In function ‘main’:
foo.c:167:19: warning: ‘ende’ is used uninitialized in this function [-Wuninitialized]
     } while (ende == false);
                   ^
foo.c:169:3: warning: ‘neustart’ is used uninitialized in this function [-Wuninitialized]
   } while (neustart == true);
   ^

Lines 18,19: Either explicitly initialize the entire game board when you declare it, or drop the initialization brackets from the declaration and just use leereSpielfeld.
Line 85: When using scanf with %s, you don't need an &. The name of an array without the [ ] is the address of the first element.
Lines 101, 107: You may have issues with order of operations here. The warning implies that somewhere, you have a parenthesis out of place, or you mixed up || and &&. See below
Line 167, 169: ende and neustart need values before you compare them. Check the return value from naechsterZug(), spielfeldAusgeben(), pruefeGewinn(), and spielfeldVoll() function calls in main to determine whether you should end the game, play again, etc. Set ende and neustart accordingly.

I found your mistake on lines 101 and 107 by putting each nesting level on it's own line with different indentation. However, that's the tedious way. It would be better if you had functions that check a row, column or diagonal for a win, and used those in combination.

Code:

bool checkRowWin(int row, char symbol)
{
    use a loop to check if specific row contains only specified symbol -- if so, return true, else false
}
// checkColumnWin and checkDiagonalWin will be similar
bool checkAllWin(char symbol)
{
    use loops to check all row, column wins
    check diagonal win
}
...
bool pruefeGewinn() {
    // this function becomes so simple!
    return checkAllWin(kreuz) || checkAllWin(kreis);
}

101 & 107 did i fixed, just set the round bracket at the end of these two lines and delete one at the far end. Your solution looks pretty nice and I will try it when the programm works. I also fixed the "&" in line 85 and the brackets at the beginning of the 2 dem. array.
There is a little problem with understanding the return value. I tried many ways but it still wont work for me with the values of pruefeGewinn() and spielfeldVoll(). I have no idea how to include the returns of these in main and how they working. I thought if i have

Code:

bool test(){
    bool value = true;
    
    if(1 > 10){
        value = false;
    }
    return value;
}

int main(int argc, char** argv) {
    bool value;
    do{
        test();
        
    }while(value != false);   
}

it will work.
Can you explain why this wouldn't work? Does I include the name of the value in the function like test(value) or something? Maybe you can correct it for me so I can understand.
Thanks in advance!

No, the variable called value in main() has nothing to do with the variable called value in test(). This is due to variable scope (read up in your textbook). You need to set value in main() based on what test() returns. You have a few options:

Code:

value = test();  // value is true if test is true, false if false
value = !test();  // value is true if test is false, false if test is true
if (test()) {
    value = true;  // or false, depending on what you want
}

THANK YOU!!! People on cprogramming are awesome!
A funny thing to notice is that when i finished the programm three weeks ago, it was disaster and as a tapeworm.
By the way the .exe shrinked from 181 KB to to now 62 KB with the same range of functions and definitly a better performance.
On one of these days I will try anduril462s idea with the win function.

Code:

#include <stdio.h> // In- and Output
#include <stdlib.h> // Implementation of many functions
#include <stdbool.h> // Allows in C99 True and False as Boolean
#include <time.h> // Allows using Random by time

/*----------------------- Constants -------------------------*/

#define KANTENLAENGE 3
#define STRING 100

const char leer = ' ';
const char kreuz = 'X';
const char kreis = 'O';

/*-------------------- Global Variables --------------------*/

char spielfeld[KANTENLAENGE][KANTENLAENGE];

int siege_kreis = 0; // Wins loop
int siege_kreuz = 0; // Wins cross

/*------------------------ Functions ------------------------*/

void starteSpiel() {
    printf("-----------------------------------------------------------------\n");
    printf("-------------------------- Tic Tac Toe --------------------------\n");
    printf("-----------------------------------------------------------------\n");
    printf("Willkommen bei dem Spiel. Es wird gestartet. \n");
    printf("Geben Sie die Koordinaten in dieser Form ein: Bsp. \"23\" = 2 und 3\n\n");
}

void leereSpielfeld() { // Clear the game of Os and Xs
    for (int i = 0; i < KANTENLAENGE; i++) {
        for (int j = 0; j < KANTENLAENGE; j++) {
            spielfeld[i][j] = leer;
        }
    }
}

void spielfeldAusgeben() { // Output for player to see the playing field

    printf("-----------------------------------------------------------------\n");
    printf("    ");
    for (int i = 0; i < KANTENLAENGE; i++) {
        int zahl_x;
        zahl_x = i + 1; // Arrays start with 0, now with 1
        printf("  %i", zahl_x);
    }
    printf("\n");

    for (int i = 0; i < KANTENLAENGE; i++) {
        int zahl_y;
        zahl_y = i + 1; //Arrays start with 0, now with 1
        printf("\n  %i  ", zahl_y);
        for (int j = 0; j < KANTENLAENGE; j++) {// Playing filed
            printf("<%c>", spielfeld[i][j]);
        }
    }
    printf("\n-----------------------------------------------------------------\n");

}

int naechsterZug(int zufall) { // Next draw of O or X and proofing of field is free

    int ersteKoordinate;
    int zweiteKoordinate;
    char amZug;
    bool eingabeOK = true;

    if (zufall != 1) {
        zufall++;
        amZug = kreuz;

    } else {
        zufall--;
        amZug = kreis;
    }
    printf("Bitte Koordinaten fuer Spieler %c eingeben (Zeile Spalte): ", amZug);
    do {
        char eingabe[STRING];
        scanf("%s", eingabe);
        int ascii = 48;
        ersteKoordinate = eingabe[0] - ascii;
        zweiteKoordinate = eingabe[1] - ascii;
        if (ersteKoordinate <= 0 || ersteKoordinate >= 4 || zweiteKoordinate <= 0 || zweiteKoordinate >= 4 || (!(spielfeld[ersteKoordinate - 1][zweiteKoordinate - 1] == ' '))) {
            eingabeOK = false;
            printf("\nFalsche Eingabe. Bitte erneut: ");
        } else {
            eingabeOK = true;
        }
    } while (eingabeOK != true);
    spielfeld[ersteKoordinate - 1][zweiteKoordinate - 1] = amZug;
    return zufall;
}

bool pruefeGewinn() { // Check if X or O has won
    int zufall;
    bool ende = false;
    if (((spielfeld[0][0] == kreuz) && (spielfeld[0][1] == kreuz) && (spielfeld[0][2] == kreuz)) || ((spielfeld[1][0] == kreuz) && (spielfeld[1][1] == kreuz) && (spielfeld[1][2] == kreuz)) || ((spielfeld[2][0] == kreuz) && (spielfeld[2][1] == kreuz) && (spielfeld[2][2] == kreuz)) || ((spielfeld[0][0] == kreuz) && (spielfeld[1][0] == kreuz) && (spielfeld[2][0] == kreuz)) || ((spielfeld[0][1] == kreuz) && (spielfeld[1][1] == kreuz) && (spielfeld[2][1] == kreuz)) || ((spielfeld[0][2] == kreuz) && (spielfeld[1][2] == kreuz) && (spielfeld[2][2] == kreuz)) || ((spielfeld[0][0] == kreuz) && (spielfeld[1][1] == kreuz) && (spielfeld[2][2] == kreuz)) || ((spielfeld[0][2] == kreuz) && (spielfeld[1][1] == kreuz) && (spielfeld[2][0] == kreuz))) {
        printf("\nSpieler Kreuz hat gewonnen!\n");
        siege_kreuz++;
        zufall = true;
        return ende = true;
    } else {
        if (((spielfeld[0][0] == kreis) && (spielfeld[0][1] == kreis) && (spielfeld[0][2] == kreis)) || ((spielfeld[1][0] == kreis) && (spielfeld[1][1] == kreis) && (spielfeld[1][2] == kreis)) || ((spielfeld[2][0] == kreis) && (spielfeld[2][1] == kreis) && (spielfeld[2][2] == kreis)) || ((spielfeld[0][0] == kreis) && (spielfeld[1][0] == kreis) && (spielfeld[2][0] == kreis)) || ((spielfeld[0][1] == kreis) && (spielfeld[1][1] == kreis) && (spielfeld[2][1] == kreis)) || ((spielfeld[0][2] == kreis) && (spielfeld[1][2] == kreis) && (spielfeld[2][2] == kreis)) || ((spielfeld[0][0] == kreis) && (spielfeld[1][1] == kreis) && (spielfeld[2][2] == kreis)) || ((spielfeld[0][2] == kreis) && (spielfeld[1][1] == kreis) && (spielfeld[2][0] == kreis))) {
            printf("\nSpieler Kreis hat gewonnen!\n");
            siege_kreis++;
            zufall = false;
            ende = true;
        }
    }
    return ende;
}

bool spielfeldVoll() { // Proofing if there is a place to put another X or O
    bool ende = false;
    int zaheler_unentschieden = 0;
    for (int i = 0; i < KANTENLAENGE; i++) {
        for (int j = 0; j < KANTENLAENGE; j++) {

            if (spielfeld[i][j] != leer) {
                zaheler_unentschieden++;
                if (zaheler_unentschieden >= 9) {
                    printf("\nUnentschieden!\n");
                    ende = true;
                }
            }
        }
    }
    return ende;
}

bool neustarten() { // Restart to play again
    bool neustart = true;
    int erneut;
    do {
        printf("\nErneut spielen? Ja = 1, Nein= 0: ");
        scanf("%i", &erneut);
    } while (!(erneut == 0 || erneut == 1));

    if (erneut == 0) {
        neustart = false;
    }
    return neustart;
}

int main(int argc, char** argv) { // Main function to call out functions

    starteSpiel();

    srand(time(NULL));
    int zufall;
    zufall = rand() % 2; // Random choose witch player starts
    bool neustart;
    do {
        leereSpielfeld();
        spielfeldAusgeben();
        bool ende;
        do {
            zufall = naechsterZug(zufall);
            spielfeldAusgeben();
            ende = pruefeGewinn();
            if(ende == false){
                ende = spielfeldVoll();
            }
        } while (ende != true);
        neustart = neustarten(); // Restart
    } while (neustart != false);

    printf("\nKreuz hat %i Siege und Kreis hat %i Siege.\n\n", siege_kreuz, siege_kreis); // Numbers of wins

    return (EXIT_SUCCESS);
}