Thread: a reverse function

Also I again missed the ==! But despite that the code fails!

I got the problem but don't get how to fix it!
Since I use:

Code:

for (i=0;i<MAX_IP_DATA_ROWS;i++)
		 {
		   i_data[i] = (char *)malloc(sizeof(data[i]));
		   i_data[i]=data[i];
		 }

when I change anything in i_data the same change is copied in data too!Can do something so that only values are copied?

Thanks,
Angkar

Here it is:

Code:

void invert(char *data[],int p1,int p2)
{
	//printf("\n Inversion");
	int i,j=0;
	int diff = abs(p2-p1);
	char *val;
	char *i_data[MAX_IP_DATA_ROWS];
	for (i=0;i<MAX_IP_DATA_ROWS;i++)
		 {
		   i_data[i] = (char *)malloc(sizeof(data[i]));
		   i_data[i]=data[i];
		 }


	//printf("Hi%s\n",data[0]);

	if (diff==1)
		{
			val = rev_sign(i_data[p1]);
			strcpy(i_data[p1],val);
		}
	
	else
	{
		int start;
		int end;
		for (start = p1,end = p2-1;start<=end;start++,end--)
		{
			val = rev_sign(data[start]);
			strcpy(i_data[end],val);
			val = rev_sign(data[end]);
			strcpy(i_data[start],val);

		}

		
	}

	while(j<MAX_IP_DATA_ROWS)
	{
		puts(i_data[j]);
		j++;
	}
	
			
}

char * rev_sign(char *ip)
{
	if(ip[0]=='+')
		ip[0]='-';
	else
		ip[0]='+';
	return ip;
}

Again, I'm too weak in pointers. Please help me rectify my errors!

If you are so weak in pointers, why do you bother trying to make an array of strings? Why must you have an array of strings anyway?

Again my advice is to simplify your life. Start the program over and just use strings. Once the program works the way you want, you now have a firm grasp of the logic.

Then if you simply have to you can get it to work with arrays of strings if you really want to. At least with this design method in mind you can't totally ruin the program's logic while your doing something.