maxGCD

In the maxGCD problem i take timeout for the last 3 test cases.
Can you see my code here: http://www.z-trening.com/new/www/html/submit.php?submit=7100024153&subm_code=1 and tell me if i can improve that?

Here is something i notced:

for(i=0;i<n;i++)
   for(j=0;j<n;j++)
// with this you check the same combination two times...

for(i=0;i<n;i++)
   for(j=i-1;j>=0;j--)
// on this way you become much more time  ...
// and you dont need to check that:
(i!=j)

First, use scanf/printf instead of cin/cout.

Second, try replacing this.

  for (int i=0;i<n;i++)
    {
        for (int j=0;j<n;j++)
        {

with this :

  for (int i=0;i<n - 1;i++)
    {
        for (int j=i + 1;j<n;j++)
        {

.
That should fix the TLE.

Thank you guys.
It fixed the TLE.

One more question.
Why should i use printf and scanf instead of cout and cin?

printf and scanf are faster