tic tac toe in c

#include<stdio.h>
int n;
int i=0;
int j=0;
char box[16][16];
int p=0;
char a=' ';
char p1[10];
char p2[10];
int r;
int c;
int x;
int y;
void name()
{
    printf("\t\tWelcome To My game\n");
    printf("\t\t   Tic Tac Toe\n");
}
void settings()
{
    printf("Enter the name of two players:");
    scanf("%s %s",p1,p2);
    printf("Name of 1st player is %s \n",p1);
    printf("Name of 2nd player is %s\n",p2);
    printf("Symbol of %s is:X\n",p1);
    printf("Symbol of %s is:O \n",p2);
    printf("%s will start this game\n",p1);
}
void size()
{
    printf("Enter the board size:");
    scanf("%d",&n);
}
void board()
{
    for(i=0;i<n;i++)
    {
        for(j=0;j<n;j++)
        {
            box[i][j]=a;
            printf("| %c |",box[i][j]);
        }
        putchar('\n');
    }
}
void game()
{
    while(p<(n*n)-1)
    {
        printf("%s's turn:\n",p1);
        printf("Enter row:");
        scanf("%d",&r);
        printf("Enter column:");
        scanf("%d",&c);
        box[r][c]='X';
        p++;
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                if (i==r&&j==c)
                {
                    box[i][j]=box[r][c];
                }
                printf("| %c |",box[i][j]);
            }
            putchar('\n');
        }
        printf("%s's turn:\n",p2);
        printf("Enter row:");
        scanf("%d",&x);
        printf("Enter column:");
        scanf("%d",&y);
        box[x][y]='O';
        p++;
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                if (i==x&&j==y)
                {
                    box[i][j]=box[x][y];
                }
                printf("| %c |",box[i][j]);
            }
            putchar('\n');
        }
    }
}
void output()
{
    if((i==j)&&(box[i][j]='X'))
    {
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                printf("%s Win",p1);
                break;
            }
        }
    }
    else if((i==j)&&(box[i][j]='O'))
    {
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                printf("%s Win",p2);
                break;
            }
        }
    }
    else if(box[i][j]='X')
    {
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                printf("%s Win",p1);
                break;
            }
        }
    }
    else if(box[i][j]='O')
    {
        for(i=0;i<n;i++)
        {
            for(j=0;j<n;j++)
            {
                printf("%s Win",p2);
                break;
            }
        }
    }
    else if(box[i][j]='X')
    {
        for(j=0;j<n;j++)
        {
            for(i=0;i<n;i++)
            {
                printf("%s Win",p1);
                break;
            }
        }
    }
    else if(box[i][j]='O')
    {
        for(j=0;j<n;j++)
        {
            for(i=0;i<n;i++)
            {
                printf("%s Win",p2);
                break;
            }
        }
    }
    else if(box[i][j]='X')
    {
        for(j=n-1;j>=0;j--)
        {
            for(i=0;i<n;i++)
            {
                printf("%s Win",p1);
                break;
            }
        }
    }
    else if(box[i][j]='O')
    {
        for(j=n-1;j>=0;j--)
        {
            for(i=0;i<n;i++)
            {
                printf("%s Win",p2);
                break;
            }
        }
    }
    else
    {
        printf("Match Draw");
    }
}
int main()
{
    name();
    settings();
    size();
    board();
    game();
    output();
    return 0;
}