Thread: File I/O Issue

howdy boys and girls:

ok i'm reading in a file for a binary tree where the left subtree of a node is in parentheses following the node key and the right subtree follows by a comma:

ie: 1(2,3(10),4(5(8),6(9),7)

would result in 1 at root 2 at left and 4 at right .. this is just the first branch..

my function pulls in this file using ifstream scanned into a char array, i'd use integer but got loads of errors...

Code:

char str[82];
	ifstream b_file("./BinaryTree.dat");
	b_file>>str;
	cout<<str<<endl;
	

	for(int i=0;i<strlen(str);i++)
	{
		if(str[i] == '(')
			{i++;  cout<<"Insert Left Subtree"<<endl;}
		else if(str[i] == ',')
			{i++;  cout<<"Insert Right Subtree"<<endl;}
		else if(str[i] == ' ')
			{i++;  cout<<"Ignoring Blank Space"<<endl;}
		else{cout<<strcat(str[i--],str[++i])<<endl;}
		cout<<str[i]<<endl;
	}
	b_file.close();

my problem i learned was handling two and then will be 3 digit numbers... i guess i should cat them together but how? or, how would i go about using an int array? then if so how should i attack my problem of sorting to various branches?

thanks for your time

thanks for the response i like that method a ton better but am confused by one thing:

Code:

 case ')':if(in >> child);else break;//read following ',' fall through

i cant tell what if(in >> child); is testing for!
from what i can tell, this line doesn't do anything?? please can you explain a little clearer for me?

thanks

ah yes that is definately clearer. however as i looked back on it my example was flawed!

binarytree.dat should look like
1(2,3(10)),4(5(8),6(9),7)

after the 10 two parenthesis.. causing this output to reach only ten, then if i modify the binarytree.dat to loose the double parentheses after the ten, it will work, however i need them as it is the entire left branch of the tree!

i tried adding a continue on that confusing line and it will iterate to the end but looses about half the values and i get the "unknown char" message. i also added a break and got the same result, i am currently modifing it now and appreciate you quick and helpful responses.

thanks!

here is some more info

when making the line look like

Code:

 case ')':if(in >> child) continue;else break;//read following ',' fall through

it will iterate through the file, but those unkown chars appear for 6 and 7, both of which follow commas. so i'm guessing once i continue i ruin the flow of the switch. tryin to think of a workaround to handle situations with '))' ..

thats what i'm trying right now!

thanks again

thanks Sorensen, the line now works and reads as follows

Code:

case ')':if(in >> child){while(child != ',')		in >>child;}else break;

now i'm on my way to actually build the tree with the class i have.

thanks again