Calculate range of data types using C++

C++ program for printing the range data type like int, char, short. Signed Data Types

METHOD
1.) calculate total number of bits by multiplying sizeof with 8 (say n)
2.) Calculate -2^(n-1) for minimum range
3.) Calculate (2^(n-1))-1 for maximum range

Output:

signed char: -128 to 127
signed int: -2147483648 to 2147483647
signed short int: -32768 to 32767

Unsigned Data Types

METHOD
1.)Find number of bits by multiplying result of sizeof with 8 say n
2.)minimum range is always zero for unsigned data type
3.)for maximum range calculate 2^n-1

Output:

unsigned char: 0 to 255
unsigned int: 0 to 4294967295
unsigned short int: 0 to 65535