Find the Five Busiest Client IPs in Request Logs

During an API traffic incident, find the five client IP addresses with the most completed request-log entries across several files. Ignore background-service messages and auxiliary messages that mention an IP without recording a request. Implement `top_request_ips(files: string[][]) -> string[][]`. Each inner input array contains the lines of one file. Return rows `[ip,count]`, ordered by descending numeric count and then by ascending numeric IPv4 address. Return fewer than five rows if fewer than five distinct client addresses occur. ### Constraints & Assumptions The source provides file logs with HTTP request lines, background messages, and a separate `Client IP=` redirect diagnostic. Passing file contents directly and the deterministic tie order are explicit practice choices. - At most 20 files and 200000 lines in total; total input length is at most 20000000 characters. - A counted line contains a request portion of the form `METHOD URL HTTP/version`, followed later on that same line by ` from A.B.C.D:port - status`. METHOD is one of GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS. Version is 1.0, 1.1, or 2.0. Status is exactly three decimal digits. - Request-line quote characters may be escaped with backslashes, as in the reported logs. Match the request and client-address fields, not an assumed fixed quote position. - Counted lines have exactly one such request/client pair. Other lines have no complete pair, even if they contain `Client IP=` or an isolated `from` substring. - IPv4 octets are decimal integers from 0 to 255 with no leading zeroes except `0`; ports are decimal integers from 1 to 65535. IPv6, forwarded-header interpretation, multiline records, and malformed request fields are outside this practice contract. - Count every completed request line once, including non-2xx statuses, repeated request IDs if any, private IPs, and lines in different files. Ignore the port when grouping. No file-overlap deduplication is implied. - Return counts as ordinary decimal strings. Numeric IPv4 tie order compares the four integer octets left to right, not the textual address strings. ### Example ```text files = [[ 'time="t" msg="GET https://api.example/a HTTP/2.0 from 10.0.0.2:12 - 200 4B"', 'time="t" msg="redirecting" Client IP="10.0.0.9:15"', 'time="t" msg="POST https://api.example/b HTTP/1.1 from 10.0.0.2:13 - 500 0B"' ], [ 'time="t" msg="GET https://api.example/c HTTP/1.1 from 10.0.0.10:14 - 200 4B"', 'time="t" msg="no pending executions"' ]] result = [["10.0.0.2","2"],["10.0.0.10","1"]] ``` Explain how you would read an actual archive incrementally without loading all files into memory. Distinguish a high request count from proof that an address is malicious. ```hint Count the event, not every address mention First identify a completed HTTP request record. Its `from` field supplies the client address; a separate diagnostic for the same request is not another request. ```