cin chars and insert them into a 2d array

Question

I would like to read from a file using cin and redirection and place them into a 2d array. Unfortunately, I keep getting a segfault because of the blank spaces after the input file, (I've checked and there are no blank spaces after the last character. Here's what I have.

input.txt

abcd
efgh
ijkl
mnop

Here's a snippet of my code:

char c; 
int i =0; int j=0;

while(cin >> c){
    ary[i][j] = c; 
    ++i; 
    ++j;
    }

The goal is to have a matrix like this:

['a', 'b', 'c', 'd']
['e', 'f', 'g', 'h']
['i', 'j', 'k', 'l']
['m', 'n', 'o', 'p']

Is there a way to tell cin to ignore all blank spaces or newlines after the letter p? I tried cin.get(c) and that doesn't seem to do the trick. Here's how I'm running my script: ./executable < input.txt

Thanks in advance

Answer 1

Run the script in your head. See what output it provides. You will clearly see you can never reference ary[0][1], ary[0][2], etc.

Did you try using debugger? It's a really useful tool.

Anyway; you need to do something different - I suggest you using for loop:

for(int i = 0; i < 4; ++i)
{
   for(int j = 0; j < 4; ++j)
   {
       std::cin >> tab[i][j];
   }
}

Usually if you're operating on tabs or input with fixed size(like yours), you want to use for loop - easier to manage