Write a function that returns a decimal number from a binary string. The function header is as follows int bin2 Dec (const strings binarystring) For example, binarystring 10001 is 17 (1 x 2^4 0 x 2^3 0 x 2^2 0 x 2 + 1 x 2^0 = 17) So, bin2 Dec ("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) returns 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