Problems with cout c++

Question

I was just watching a video on youtube about an akm function and i tried to implement it.
I actually wrote a code and forgot to make spaces between the variables(for an easy reading), but the program didn't print anything but it kept on calculating.

I thought that a similar syntax would work just fine. Is there something I am doing wrong ?
Here is the code :

#include <bits/stdc++.h>
using namespace std;

int akm(int m,int n) {
    if(m==0) return n+1;
    else if(n==0) return akm(m-1,1);
    else return akm(m-1 , akm(m,n-1));
}

int main() {
  for(int i=0;i<6;i++)
      for(int j=0;j<6;j++) {
          cout<<i<<" "<<j ;
          cout<<akm(i,j);
      }
 }

Unrelated: `#include using namespace std;` leads me to suggest you watch different videos. That combination of bad ideas can lead to astoundingly strange errors. Read [Why is “using namespace std” considered bad practice?](https://stackoverflow.com/questions/1452721/why-is-using-namespace-std-considered-bad-practice) and [Why should I not #include ?](https://stackoverflow.com/questions/31816095/why-should-i-not-include-bits-stdc-h) for more information on why you don't want to use either statement alone. — user4581301, Mar 20 '19 at 20:35
Are you sure your program isn't just taking very long? You're not flushing on every write, so it will only flush when the program exits — KABoissonneault, Mar 20 '19 at 20:37
YUP I did try it also on many platforms but as always no output — Salim Hertelli, Mar 20 '19 at 20:37
Sorry to link my own answer as a duplicate (there are many more to find), that was just by chance findinf it via google. — πάντα ῥεῖ, Mar 20 '19 at 20:38
I suspect it never gets to the `cout` statement. Good odds the recursion runs off the end of the stack. — user4581301, Mar 20 '19 at 20:38
I know that the program should take so long to exectue( and i mean sooo long) — Salim Hertelli, Mar 20 '19 at 20:38
If the program is taking a while to complete, you should probably flush the stream on every print. `std::cout << i << " " << j << "\n" << std::flush;` or `std::cout << i << " " << j << std::endl;` — KABoissonneault, Mar 20 '19 at 20:40
here is the video for those intrested : https://www.youtube.com/watch?v=i7sm9dzFtEI — Salim Hertelli, Mar 20 '19 at 20:40
OK. Looks like the video wasn't the source of the bad advice about `bits` and `using namespace std;`. That was all C code, but wherever you got that opener from, be careful with it. If you find yourself with a multi-page crawl of inscrutable error messages, it should be the first thing to go. — user4581301, Mar 20 '19 at 20:51
And the program's crashing, on my PC at least, but I do get some data printed out first. That's Undefined Behaviour for you. On Alice's PC it works. On Bob's it doesn't. Except on Tuesday. — user4581301, Mar 20 '19 at 20:55

score 0 · Accepted Answer · answered Mar 20 '19 at 20:31

0

You may need to explicitly flush the output stream or print a newline which may flush the buffer on some streams:

std::cout << std::flush;

std::cout << std::endl;

answered Mar 20 '19 at 20:31

jspcal

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FWIW, `endl` doesn't just print a newline. It also flushes the buffer. – NathanOliver Mar 20 '19 at 20:32
It is working now . But why it is so ? because i never saw it before – Salim Hertelli Mar 20 '19 at 20:34
1

See: [What does flushing the buffer mean](https://stackoverflow.com/questions/15042849/what-does-flushing-the-buffer-mean) – AlbertM Mar 20 '19 at 20:41
The output is buffered by default and won't be sent until the buffer is full or explicitly flushed. It's more efficient to write data in chunks. – jspcal Mar 20 '19 at 20:43

Problems with cout c++

1 Answers1