Some cstdlib function prototypes

• int abs(int j) - absolute value of j
• long labs(long j) - absolute value of j
• int atoi(const char n[]) - converts the c-style string n to an int
• long atol(const char n[]) - converts the c-style string n to a long
• double atof(const char n[]) - converts the c-style string n to a double
• int rand() - returns a pseudo random number in the range 0..RAND_MAX inclusive.
• void srand(unsigned int seed) - uses the argument seed to start a pseudo random number sequence