Segmentation fault

cooljaini (1)
// hey can anybody help me with my code of tic tac toe game.. m getting segmentation fault

//Two player game of tic tac toe

#include<stdio.h>

int a[2][2]={0,0,0,0,0,0,0,0,0};
int pos1,pos2,flag=0,max=0;
void fill(int flag)
{
int l,m,n;
while(max<=9)
{
if(flag%2==0)
{
B:
printf("Player 1 enter pos1 and pos2 varying between 0 to 2\n");
scanf("%d %d",pos1,pos2);

if(a[pos1][pos2]==4)
{
printf("Entry is invalid/already occupied\n");
goto B;
}
else
{
a[pos1][pos2]=3;
flag++;
max++;
l=check_row(pos1,pos2);
m=check_column(pos1,pos2);
if(l==1 || m==1)
{result(flag);}
if((pos1-pos2)%2==0)
{
n=check_diagonal(pos1,pos2);
if(n==1)
{result(flag);}
}
}
}
else
{
A:
printf("Player 2 enter pos1 and pos2 varying between 0 to 2\n");
scanf("%d %d",pos1,pos2);

if(a[pos1][pos2]==3)
{
printf("Entry is invalid/already occupied\n");
goto A;
}
else
{
a[pos1][pos2]=4;
flag++;
max++;
check_row(pos1,pos2);
check_column(pos1,pos2);
if(l==1 || m==1)
{result(flag);}

if((pos1-pos2)%2==0)
{
check_diagonal(pos1,pos2);
if(n==1)
{result(flag);}
}

}
}
}
}


int check_diagonal(pos1,pos2)
{
int i,count=0;
if(pos1==pos2)
{
for(i=0;i<2;i++)
{
if(a[i][i]==a[i+1][i+1])
{
count++;
}
}
if(count==2)
{
return 1;
}

}
else
{
i=1;
if(a[i][i]==a[i+1][i-1]==a[i-1][i+1])
{
return 1;
}

}


}

int check_row(int pos1,int pos2)
{
if(a[pos1][0]==a[pos1][1]==a[pos1][2])
{return 1;}
}

int check_column(int pos1,int pos2)
{
if(a[0][pos2]==a[1][pos2]==a[2][pos2])
{return 1;}
}

result(int flag)
{
int k;
if(flag%2==0)
{
k=1;
}
else
{
k=2;
}
printf("Game over player %d wins,k");

}


void main()
{
int i;
printf("Game starts with player1\n");
fill(flag);

}
TheMassiveChipmunk (259)
I took the liberty of adding code tags and indenting your source code.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
 
#include <stdio.h>

int a [2] [2] =
{
    0 , 0 ,0 , 0 , 0 ,0 , 0 , 0 , 0
};

int pos1 = 0 , pos2 = 0, flag = 0 , max = 0;

void fill(int flag)
{
    int l = 0 , m = 0 , n = 0;
    while(max <= 9)
    {
	if(flag % 2 == 0)
	{
	B:
	    printf ("Player 1 enter pos1 and pos2 varying between 0 to 2\n");
	    scanf ("%d %d", &pos1 , &pos2); //Scanf needs the address of the variable
	    
	    if(a [pos1][pos2] == 4)
	    {
		printf ("Entry is invalid/already occupied\n");
		goto B;
	    }
	    else
	    {
		a[pos1][pos2] = 3;
		flag++;
		max++;
		l = check_row (pos1 , pos2);
		m = check_column (pos1 , pos2);
		if(l ==1 || m==1)
		{
		    result(flag);
		}
		if((pos1 - pos2) % 2 ==0 )
		{
		    n = check_diagonal(pos1 , pos2);
		    if(n == 1)
		    {
			result(flag);
		    }
		}
	    }
	}
	else
	{
	A:
	    printf ("Player 2 enter pos1 and pos2 varying between 0 to 2\n");
	    scanf ("%d %d", &pos1 , &pos2); //Scanf needs the address of the variable
	    
	    if(a[pos1][pos2] == 3)
	    {
		printf ("Entry is invalid/already occupied\n");
		goto A;
	    }
	    else
	    {
		a[pos1][pos2] = 4;
		flag++;
		max++;
		check_row (pos1 , pos2);
		check_column (pos1 , pos2);
		if(l == 1 || m == 1)
		{
		    result(flag);
		}
		if((pos1 - pos2) % 2 == 0)
		{
		    check_diagonal(pos1 , pos2);
		    if(n == 1)
		    {
			result(flag);
		    }
		}
		
	    }
	}
    }
}


int check_diagonal(pos1 , pos2)
{
    int i , count = 0;
    if(pos1 == pos2)
    {
	for(i = 0 ; i < 2 ; i++)
	{
	    if(a [i][i] == a[i+1][i+1])
	    {
		count++;
	    }
	}
	if(count == 2)
	{
	    return 1;
	}
	
    }
    else
    {
	i = 1;
	if(a[i][i]== a[i+1][i-1] == a[i-1][i+1])
	{
	    return 1;
	}
	
    }
    
    
}

int check_row(int pos1 , int pos2)
{
    if(a[pos1][0] == a[pos1][1] ==a[pos1][2])
    {
	return 1;
    }
}

int check_column(int pos1 , int pos2)
{
    if(a[0][pos2] == a[1][pos2] == a[2][pos2])
    {
	return 1;
    }
}

void result(int flag)
{
    int k = 0;
    if(flag % 2==0)
    {
	k = 1;
    }
    else
    {
	k = 2;
    }
    printf ("Game over player %d wins,k");    
}


int main (int argc , char* argv []) //Don't use void main
{
    int i = 0;
    printf ("Game starts with player1\n");
    fill (flag);
    
    return 0;
}


Off the top of my head I see you are using gotos which are bad , void main () , and scanf needs the address of the variable.
closed account (DSLq5Di1)
int a[2][2]={0,0,0,0,0,0,0,0,0};

A few too many zeros there. You are going out of bounds in a few places too.


                             a[0][0]
                           -----------> 0 
                   a[0]   |
                ----------|
               |          |  a[0][1]
               |           -----------> 0 
               |
 int a[2][2] --|
               |             a[1][0]
               |           -----------> 0 
               |   a[1]   |
                ----------|
                          |  a[1][1]
                           -----------> 0
eypros (329)
Just as a useful tip segfaults most commonly have to do which boundary excesses. That is arrays (or pointers as well) that exceed their limits
Topic archived. No new replies allowed.