Chapter 3, Problem 3.35E

(Printing the Decimal Equivalent of a Binary Number) Input an integer (5 digits or fewer) containing only 0s and 1s (i.e., a “binary” integer) and print its decimal equivalent. [Hint: Use the remainder and division operators to pick off the “binary” number’s digits one at a time from right to left. Just as in the decimal number system, in which the rightmost digit has a positional value of 1, and the next digit left has a positional value of 10. then 100, then 1000, and so on, in the binary number system the rightmost digit has a positional value of 1, the next digit left has a positional value of 2, then 4, then 8, and so on. Thus the decimal number 234 can be interpreted as $4*1+3*10+2*100$. The decimal equivalent of binary 1101 is $1*1+0*2+1*4+1*8or1+0+4+8or13.]$