exercism/c/binary

Binary

Welcome to Binary on Exercism's C Track. If you need help running the tests or submitting your code, check out HELP.md.

Instructions

Convert a binary number, represented as a string (e.g. '101010'), to its decimal equivalent using first principles.

Implement binary to decimal conversion. Given a binary input string, your program should produce a decimal output. The program should handle invalid inputs.

Note

• Implement the conversion yourself. Do not use something else to perform the conversion for you.

About Binary (Base-2)

Decimal is a base-10 system.

A number 23 in base 10 notation can be understood as a linear combination of powers of 10:

• The rightmost digit gets multiplied by 10^0 = 1
• The next number gets multiplied by 10^1 = 10
• ...
• The nth number gets multiplied by 10^(n-1).
• All these values are summed.

So: 23 => 2*10^1 + 3*10^0 => 2*10 + 3*1 = 23 base 10

Binary is similar, but uses powers of 2 rather than powers of 10.

So: 101 => 1*2^2 + 0*2^1 + 1*2^0 => 1*4 + 0*2 + 1*1 => 4 + 1 => 5 base 10.

Source

Created by

• @antony-jr

Contributed to by

• @bcc32
• @deathsec
• @Gamecock
• @h-3-0
• @patricksjackson
• @QLaille
• @RealBarrettBrown
• @ryanplusplus
• @wolf99

Based on

All of Computer Science - https://www.wolframalpha.com/examples/mathematics/numbers/base-conversions