mod.rs (revision d4726bddaa87cc4778e7472feed243fa4b6c267f) - OpenGrok cross reference for /aosp_15_r20/external/bazelbuild-rules_rust/test/rust_test_suite_shared/tests/helpers/mod.rs

// Binet's formula for checking Fibonacci numbers
pub fn is_fibonacci(x: i32) -> bool {
    is_perfect_square(5 * x * x + 4) || is_perfect_square(5 * x * x - 4)
}

fn is_perfect_square(x: i32) -> bool {
    if x < 0 {
        return false;
    }
    let y = (x as f64).sqrt() as i32;
    y * y == x
}