Tris

#include <stdio.h>
#include <stdlib.h>
#define MAX_NAME_LEN 32

void show_array(int (*)[3]);
void insert_xo(int (*)[3], int, int);
int check_win(int (*)[3]);
void get_players_name(char (*)[MAX_NAME_LEN+1]);
void init_array(int (*)[3]);
int get_player_move();

main(){
    char name[2][MAX_NAME_LEN+1];
    int array[3][3], player_id=0;
    init_array(array);
    get_players_name(name);
    do{
        system("clear");
        printf("%sIt's your turn!\n", name[player_id]);
        show_array(array);
        insert_xo(array, get_player_move(), player_id);
        player_id^=1; /* change player */
    }while((check_win(array))==0);
    system("clear");
    printf("%s won!\n", name[player_id^1]);
    show_array(array);
    return 0;
}

void get_players_name(char (*namePtr)[MAX_NAME_LEN+1]){
    puts("Hi player 1, what's your name?");
    fgets(namePtr[0], MAX_NAME_LEN, stdin);
    system("clear");
    puts("Hi player 2, what's your name?");
    fgets(namePtr[1], MAX_NAME_LEN, stdin);
}

void init_array(int (*arrayPtr)[3]){
    int i, j;
    for(i=0;i<3;i++)
        for(j=0;j<3;j++)
            arrayPtr[i][j]=-99;
}

void show_array(int (*arrayPtr)[3]){
    int i, j;
    for(i=0;i<3;i++){
        printf("|");
        for(j=0;j<3;j++)
            if(arrayPtr[i][j]<0)
                printf("%d|", 1+j+3*i);
            else if(arrayPtr[i][j]==0)
                printf("O|");
            else if(arrayPtr[i][j]==1)
                printf("X|");

        puts("");
    }
}

int check_win(int (*arrayPtr)[3]){
    int check_rows(int (*)[3]);
    int check_columns(int (*)[3]);
    int check_diags(int (*)[3]);
    return (check_rows(arrayPtr)+check_columns(arrayPtr)+check_diags(arrayPtr));
}

int check_rows(int (*arrayPtr)[3]){
    int i, j, flag=0;
    for(i=0;i<3;i++)
        for(j=0;j<2;j++)
            if((arrayPtr[i][0]+arrayPtr[i][1]+arrayPtr[i][2])==(3*j))
                flag++;
    return flag;
}

int check_columns(int (*arrayPtr)[3]){
    int i, j, flag=0;
    for(i=0;i<3;i++)
        for(j=0;j<2;j++)
            if((arrayPtr[0][i]+arrayPtr[1][i]+arrayPtr[2][i])==(3*j))
                flag++;
    return flag;
}

int check_diags(int (*arrayPtr)[3]){
    int i, j, flag=0;
    for(j=0;j<2;j++)
        if((arrayPtr[0][0]+arrayPtr[1][1]+arrayPtr[2][2])==(3*j))
            flag++;
        else if((arrayPtr[2][0]+arrayPtr[1][1]+arrayPtr[2][0])==(3*j))
            flag++;
    return flag;
}

void insert_xo(int (*arrayPtr)[3], int n, int id_player){
    int r=0, c=n;
    while( n>3 ){
        r++;
        n-=3;
    }
    c-=3*r+1;
    arrayPtr[r][c]=id_player;
}

int get_player_move(){
    int n;
    do{
            scanf("%d", &n);
            if(n<0||n>9)
                puts("You have to insert a number in the 1-9 range");
        }while(n<0||n>9);
        return n;
}