What language does this DFA accept? 0 - N Y all binary strings that do not contain "11" all binary strings that end with "00" all binary strings that contain at least two zeros all binary strings that contain exactly two zeros

Construct two PDA that recognizes the following language: 1. Every prefix contains at least as many a's as b's 2. The string contains the same number of a's and b's. Hint: To get the maximum number of points, use as few states and nonterminals as possible!

Write regular expressions for following languages a) Set of binary numbers that have multiple of 4 1%. E.g., 0000, 010111, 111111110. b) Set of binary strings starting with 11 and ending with 00. E.g., 1100,1110100,1100100

Which compiler phase would generate an error if you tried to append an integer to a character string?