Skip to content

Instantly share code, notes, and snippets.

@emildoychinov

emildoychinov/ttt.c

Created January 22, 2021 10:48
Show Gist options

  • Select an option

    Learn more about clone URLs
  • Save emildoychinov/98d602dee247aa95080306d45e93713a to your computer and use it in GitHub Desktop.

Select an option

Learn more about clone URLs
Save emildoychinov/98d602dee247aa95080306d45e93713a to your computer and use it in GitHub Desktop.
Download ZIP
A simple console Tic Tac Toe game with an AI using the minimax algorithm
Raw
gistfile1.txt
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <conio.h>
#include <stdbool.h>
#include <time.h>
#include <math.h>
#define f_size 10
typedef struct ttt{
int pos;
int comp_move;
int p_move;
char comp_sign;
char p_sign;
char chr;
char diff;
char field[f_size];
}tictactoe;
void acquirechar(tictactoe *ttt){
for(int j=1; j<f_size; j++){
ttt->field[j]=ttt->chr;
}
}
void print(char field[f_size], int n){
printf("\t");
for(int i=1; i<f_size; i++){
printf("%c ", field[i]);
if(i%n==0 && i!=pow(n,2)){
printf("\n\t");
}
}
}
int getmove(tictactoe *ttt){
scanf("%d", &ttt->pos);
while(ttt->pos>9 || ttt->pos<=0){
printf("invalid position, please insert a new one : \n");
scanf("%d", &ttt->pos);
}
while(ttt->field[ttt->pos]!=ttt->chr){
printf("invalid position, please insert a new one : \n");
scanf("%d", &ttt->pos);
}
return ttt->pos;
}
int game_ended(tictactoe *ttt){
int WinningPos=0;
int WinningPosArr[10][10]={{1,2,3},{4,5,6}, {7,8,9}, {1,4,7}, {2,5,8}, {3,6,9}, {1,5,9}, {3,5,7}};
for (int i=0; i<9; ++i){
if(ttt->field[WinningPosArr[i][WinningPos]]==ttt->field[WinningPosArr[i][WinningPos+1]] && ttt->field[WinningPosArr[i][WinningPos]]==ttt->field[WinningPosArr[i][WinningPos+2]]){
if(ttt->field[WinningPosArr[i][WinningPos]]==ttt->p_sign){
return -1;
}
else if(ttt->field[WinningPosArr[i][WinningPos]]==ttt->comp_sign){
return 1;
}
}
}
return 0;
}
int minimax(tictactoe ttt, int pl){
int win=game_ended(&ttt);
if(win!=0){
return win*pl;
}
int score=-10;
int move=-10;
int moveScore;
for(int i=1; i<=9; ++i){
if(ttt.field[i]==ttt.chr){
ttt.field[i]=(pl==-1) ? ttt.p_sign : ttt.comp_sign;
moveScore=-minimax(ttt, -pl);
if(moveScore>score){
score=moveScore;
move=i;
}
ttt.field[i]=ttt.chr;
}
}
if(move==-10){
return 0;
}
return score;
}
int makeMove(tictactoe ttt){
int score=-10;
int move;
int thisScore;
for(int j=1; j<=9; j++){
if(ttt.field[j]==ttt.chr){
ttt.field[j]=ttt.comp_sign;
int thisScore = -minimax(ttt, -ttt.comp_move);
ttt.field[j]=ttt.chr;
if(thisScore>score){
score=thisScore;
move=j;
}
}
}
return move;
}
void whoWins(tictactoe *ttt){
switch (game_ended(ttt)){
case -1:
printf("\nThe game has ended. The player wins!\n");
break;
case 1:
printf("\nThe game has ended. The computer wins!\n");
break;
case 0:
printf("\nThe game has ended. It is a draw!\n");
break;
}
}
int main(void){
srand(time(0));
tictactoe ttt;
printf("\nHi, player! Do you want your game to be (e)asy or (h)ard? " );
scanf(" %c", &ttt.diff);
printf("Please choose a character for the board to be made of : ");
scanf(" %c", &ttt.chr);
while(ttt.chr=='X' || ttt.chr=='O'){
printf("Invalid character, please enter a new one : ");
scanf(" %c", &ttt.chr);
}
acquirechar(&ttt);
printf("\nDo you want to be first or second?(1/2) ");
scanf("%d", &ttt.p_move);
while(ttt.p_move>2 || ttt.p_move<1){
printf("You can't be %d, there is no such turn! Please enter a valid position (1/2) ", ttt.p_move);
scanf("%d", &ttt.p_move);
}
ttt.p_sign = (ttt.p_move==1) ? 'X' : 'O';
ttt.comp_sign = (ttt.p_move==1) ? 'O' : 'X';
ttt.comp_move=1;
ttt.p_move=-1;
printf("\n");
for(int steps=0; game_ended(&ttt)==0 && steps<9; ++steps){
print(ttt.field, 3);
if(steps%2==0){
printf("\nPlayer one, enter a position : ");
if(ttt.p_sign=='X'){
getmove(&ttt);
}
else {
ttt.pos=(ttt.diff=='e') ? rand()%9 : makeMove(ttt);
while(ttt.field[ttt.pos]!=ttt.chr){
ttt.pos=rand()%9;
}
printf(" %d\n", ttt.pos);
}
}
else{
printf("\nPlayer two, enter a position : \t");
if(ttt.p_sign=='O'){
getmove(&ttt);
}
else{
ttt.pos=(ttt.diff=='e') ? rand()%9 : makeMove(ttt);
while(ttt.field[ttt.pos]!=ttt.chr){
ttt.pos=rand()%9;
}
printf(" %d\n", ttt.pos);
}
}
if(steps%2==0){
ttt.field[ttt.pos]='X';
}
else {
ttt.field[ttt.pos]='O';
}
}
whoWins(&ttt);
printf("The final board is \n\n");
print(ttt.field, 3);
getch();
}
Raw
ttt.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <conio.h>
#include <stdbool.h>
#include <time.h>
#include <math.h>
#define f_size 10
typedef struct ttt{
int pos;
int comp_move;
int p_move;
char comp_sign;
char p_sign;
char chr;
char diff;
char field[f_size];
}tictactoe;
void acquirechar(tictactoe *ttt){
for(int j=1; j<f_size; j++){
ttt->field[j]=ttt->chr;
}
}
void print(char field[f_size], int n){
printf("\t");
for(int i=1; i<f_size; i++){
printf("%c ", field[i]);
if(i%n==0 && i!=pow(n,2)){
printf("\n\t");
}
}
}
int getmove(tictactoe *ttt){
scanf("%d", &ttt->pos);
while(ttt->pos>9 || ttt->pos<=0){
printf("invalid position, please insert a new one : \n");
scanf("%d", &ttt->pos);
}
while(ttt->field[ttt->pos]!=ttt->chr){
printf("invalid position, please insert a new one : \n");
scanf("%d", &ttt->pos);
}
return ttt->pos;
}
int game_ended(tictactoe *ttt){
int WinningPos=0;
int WinningPosArr[10][10]={{1,2,3},{4,5,6}, {7,8,9}, {1,4,7}, {2,5,8}, {3,6,9}, {1,5,9}, {3,5,7}};
for (int i=0; i<9; ++i){
if(ttt->field[WinningPosArr[i][WinningPos]]==ttt->field[WinningPosArr[i][WinningPos+1]] && ttt->field[WinningPosArr[i][WinningPos]]==ttt->field[WinningPosArr[i][WinningPos+2]]){
if(ttt->field[WinningPosArr[i][WinningPos]]==ttt->p_sign){
return -1;
}
else if(ttt->field[WinningPosArr[i][WinningPos]]==ttt->comp_sign){
return 1;
}
}
}
return 0;
}
int minimax(tictactoe ttt, int pl){
int win=game_ended(&ttt);
if(win!=0){
return win*pl;
}
int score=-10;
int move=-10;
int moveScore;
for(int i=1; i<=9; ++i){
if(ttt.field[i]==ttt.chr){
ttt.field[i]=(pl==-1) ? ttt.p_sign : ttt.comp_sign;
moveScore=-minimax(ttt, -pl);
if(moveScore>score){
score=moveScore;
move=i;
}
ttt.field[i]=ttt.chr;
}
}
if(move==-10){
return 0;
}
return score;
}
int makeMove(tictactoe ttt){
int score=-10;
int move;
int thisScore;
for(int j=1; j<=9; j++){
if(ttt.field[j]==ttt.chr){
ttt.field[j]=ttt.comp_sign;
int thisScore = -minimax(ttt, -ttt.comp_move);
ttt.field[j]=ttt.chr;
if(thisScore>score){
score=thisScore;
move=j;
}
}
}
return move;
}
void whoWins(tictactoe *ttt){
switch (game_ended(ttt)){
case -1:
printf("\nThe game has ended. The player wins!\n");
break;
case 1:
printf("\nThe game has ended. The computer wins!\n");
break;
case 0:
printf("\nThe game has ended. It is a draw!\n");
break;
}
}
int main(void){
srand(time(0));
tictactoe ttt;
printf("\nHi, player! Do you want your game to be (e)asy or (h)ard? " );
scanf(" %c", &ttt.diff);
printf("Please choose a character for the board to be made of : ");
scanf(" %c", &ttt.chr);
while(ttt.chr=='X' || ttt.chr=='O'){
printf("Invalid character, please enter a new one : ");
scanf(" %c", &ttt.chr);
}
acquirechar(&ttt);
printf("\nDo you want to be first or second?(1/2) ");
scanf("%d", &ttt.p_move);
while(ttt.p_move>2 || ttt.p_move<1){
printf("You can't be %d, there is no such turn! Please enter a valid position (1/2) ", ttt.p_move);
scanf("%d", &ttt.p_move);
}
ttt.p_sign = (ttt.p_move==1) ? 'X' : 'O';
ttt.comp_sign = (ttt.p_move==1) ? 'O' : 'X';
ttt.comp_move=1;
ttt.p_move=-1;
printf("\n");
for(int steps=0; game_ended(&ttt)==0 && steps<9; ++steps){
print(ttt.field, 3);
if(steps%2==0){
printf("\nPlayer one, enter a position : ");
if(ttt.p_sign=='X'){
getmove(&ttt);
}
else {
ttt.pos=(ttt.diff=='e') ? rand()%9 : makeMove(ttt);
while(ttt.field[ttt.pos]!=ttt.chr){
ttt.pos=rand()%9;
}
printf(" %d\n", ttt.pos);
}
}
else{
printf("\nPlayer two, enter a position : \t");
if(ttt.p_sign=='O'){
getmove(&ttt);
}
else{
ttt.pos=(ttt.diff=='e') ? rand()%9 : makeMove(ttt);
while(ttt.field[ttt.pos]!=ttt.chr){
ttt.pos=rand()%9;
}
printf(" %d\n", ttt.pos);
}
}
if(steps%2==0){
ttt.field[ttt.pos]='X';
}
else {
ttt.field[ttt.pos]='O';
}
}
whoWins(&ttt);
printf("The final board is \n\n");
print(ttt.field, 3);
getch();
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment