Two's complement

🏷️ Computer science

To get the two’s complement negative notation of an integer:

• write the number in binary
• invert the digits
• add one to the result

If the leftmost bit of a two’s complement number is 1, the number is negative.

If the leftmost bit is 0, the number is 0 or **positive **

Convert from two’s complement number:

• Invert bits
• Add one to the result

Arithmetic with two’s complement

• Addiction
  • Convert numbers to binary
  • Add them
• Subtraction
  • Convert numbers to binary
  • The number after minus is converted to two’s complement number
  • Add them

https://www.cs.cornell.edu/~tomf/notes/cps104/twoscomp.html