isqrt22

isqrt22 is a lightweight command‑line utility designed to compute the integer square root of non‑negative integers efficiently. It implements the binary search algorithm combined with a localized Newton‑Raphson refinement to achieve logarithmic time complexity with fixed‑point arithmetic. The program accepts input via standard input or as command‑line arguments and outputs the floor of the square root.

The project was first released in 2022 as an open‑source contribution under the MIT license, and it has since been bundled in several Linux distributions, including Ubuntu 22.04 and Arch Linux. The source code is maintained on GitHub under the repository name isqrt22/isqrt22, where contributors can submit pull requests or report issues via the issue tracker.

isqrt22 emphasizes portability; it is written in portable C99 and contains only standard library dependencies, making it suitable for embedded environments where memory and computational resources are limited. The executable binary is typically under 30 kB when statically linked, and it offers optional flags to display timing information and detailed debugging logs.

Unlike the built‑in math.isqrt function in Python's math library, isqrt22 is intended for use in environments without scripting language support, such as microcontrollers or legacy code bases requiring fast, deterministic integer arithmetic. The tool is widely referenced in embedded systems communities, and documentation is available in both English and Spanish on the project's website.