Question

The regular expression with all strings of 0′s and 1′s with at least two consecutive 0′s is?

(a) 1 + (10)*

(b) (0+1)*00(0+1)*

(c) (0+1)*011

(d) 0*1*2*

The question was posed to me in an online interview.

My question is based upon Regular Expression topic in section Compiler Introduction of Compiler

Answer 1

The correct option is (b) (0+1)*00(0+1)*

The explanation: The expression (0+1)*00(0+1)* is where either it initially takes 0 or 1 or 00 followed by string of combination of 0 and 1.