I was looking at some of the solutions in Google Code Jam and some people used this things that I had never seen before. For example,
2LL*r+1LL What does 2LL and 1LL mean?
Their includes look like this:
#include <math.h> #include <algorithm> #define _USE_MATH_DEFINES or
#include <cmath> 1 Answer
The LL makes the integer literal of type long long.
So 2LL, is a 2 of type long long.
Without the LL, the literal would only be of type int.
This matters when you're doing stuff like this:
1 << 40 1LL << 40 With just the literal 1, (assuming int to be 32-bits, you shift beyond the size of the integer type -> undefined behavior). With 1LL, you set the type to long long before hand and now it will properly return 2^40.