Write a function that returns a decimal number from a binary string. The function header is as follows:

int bin2Dec(const string& binaryString)

For example, binaryString 10001 is 17 (1x2 ⁴ + Ox2 ³ + Ox2 ² + Ox2 ¹ +1x2 ⁰ =17). So, bin2Dec ("10001") returns 17.

Write a function that parses a decimal number into a binary number as a string. The function header is as follows:

string dec2Bin (int value)

For example. dec2Bin (17 ) rettuns string "10001".

Write a test program that prompts the user to enter a binary or decimal number and display its equivalent value in decimal or binary.