Some other important things

Fast Input/Output

• In C++, for fast input / output, while using cin and cout, use these lines :

int main()

{

ios_base::sync_with_stdio(false);

cin.tie(NULL);

cout.tie(NULL);

// all your code below this

….

}

• These above lines makes cin, cout work faster. It is advised to add these statements in all your codes.

tip

Also for fast output, don’t use cout << endl. Instead use cout << ‘\n’ for a newline. It works faster.

Avoid common mistakes

• You must become familiar with the following :

  • Common errors on online judges like TLE, MLE, Runtime error, Compile error and how to get rid of them
  • When does overflow occur ? How to prevent overflow ?
  • How to compare floating point values, like doubles ? (we can’t simply use == )

• You may refer to this great blog, to get familiar with these.

tip

To get rid of type-casting int to long long multiple times for preventing overflow, you may want to write this at the top:

#define int long long

For this to work, also replace int main() by :

int32_t main()

Session Slides

• The whiteboard slides, used during the introduction session, are available here