Implement a JSON Parser

Problem Implement a simplified JSON parser. Given a string representing a JSON value, parse it and print an equivalent compact JSON string with unnecessary whitespace removed. If the input is invalid JSON, print INVALID. Supported JSON Types object array string number boolean null String Requirements Support common escapes: quote backslash slash b, f, n, r, t unicode escape Number Requirements Support: integer negative number decimal number exponent notation Input stdin contains one JSON value, possibly with spaces and newlines. Output If the input is valid, print compact JSON. If the input is invalid, print INVALID. Constraints Input length is at most 200000. Nesting depth is at most 1000. Example Input {"a":1,"b":[true,null,"x"]} Output {"a":1,"b":[true,null,"x"]}