Function fib_cache_result

src/dp/fib.rs:19–32

(n: usize)

/// 缓存中间结果
#[allow(unused)]
pub fn fib_cache_result(n: usize) -> usize {
    match n {
        0 => 0,
        1 | 2 => 1,
        _ => match MEMO.with(|memo| memo.borrow()[n]) {
            0 => {
                let v = fib_cache_result(n - 1) + fib_cache_result(n - 2);
                MEMO.with(|memo| memo.borrow_mut()[n] = v);
                v
            }
            memo => memo,
        },
    }
}

/// 只保存前两个值，最节省内存和最快的方式
#[allow(unused)]