Introduction

Input and Output

Newline "\n" works faster than endl because endl always causes a flush operation.
Reading an entire line of input (with/without) spaces: getline(cin,s)
If amount of input data is unknown: while(cin>>x){ //code }
When using long long, convert result to same dataype, don't leave it in int.

Modular Arithmetic:

x mod m : remainder when x is divided by m.
Properties:
- (a+b) mod m = (a mod m + b mod m) mod m
- (a-b) mod m = (a mod m - b mod m) mod m
- (a.b) mod m = (a mod m . b mod m) mod m

Short Code:

Example:

typedef long long ll; typedef vector<int> vi; typedef pair<int,int> pi;

Macros:

#define PB push_back #define MP make_pair

Math Theory

Things to know:

AP. GP, HP
Set Theory
Logic:
- A => B (if when A is true, B is true)
- A <=> B (A and B are both positive or both negative)
Functions: min, max, factorial, fibonnaci (f(n) = f(n-1) + f(n-2))
Logarithms