JeanLucPons/Kangaroo — reverse-engineered prompt

Build me a fast C++ command line tool for solving secp256k1 interval discrete log problems with Pollard kangaroo, meant for research and authorized puzzle ranges only.

It should read a simple text input file with a start range, end range, and one or more public keys in hex, accepting compressed and uncompressed keys. Let it run on CPU threads, and optionally use CUDA GPUs with support for choosing one or more GPU ids. Show useful progress like range width, expected work, RAM use, distinguished point count, elapsed time, and found keys.

Please include save and resume support so long runs can continue later, plus tools to inspect and merge work files. If practical, add server and client mode so multiple machines can work together. Add options to list GPUs, verify GPU results against CPU, set threads, output results to a file, and tune distinguished point bits.

Keep the search limited to 125 bit intervals, make it easy to compile on Linux and Windows, and include clear usage examples. Look up current CUDA docs online if needed.