The government of a small but important country has decided that the alphabet needs to be streamlined and reordered. Uppercase letters will be eliminated. They will issue a royal decree in the form of a String of B and A characters. The first character in the decree specifies whether a must come ( B )Before b in the new alphabet or ( A )After b . The second character determines the relative placement of b and c , etc. So, for example, "BAA" means that a must come Before b , b must come After c , and c must come After d .
Any letters beyond these requirements are to be excluded, so if the decree specifies k comparisons then the new alphabet will contain the first k+1 lowercase letters of the current alphabet.
Create a class Alphabet that contains the method choices that takes the decree as input and returns the number of possible new alphabets that conform to the decree. If more than 1,000,000,000 are possible, return -1.
Definition
This book is intended for embedded system programmers, consultants and students interested in real-time operating
systems. μC/OS-II is a high performance, deterministic real-time kernel and can be embedded in commercial products
(see Appendix F, Licensing). Instead of writing your own kernel, you should consider μC/OS-II. You will find, as I
did, that writing a kernel is not as easy as it first looks.
VHDL編寫的4選一數(shù)據(jù)選擇器
entity mux41a is
port(a,b:in
std_logic;
s1,s2,s3,s4:in std_logic;
y:
out std_logic);
end entity mux41a;
architecture one of mux41a is
signal ab:std_logic_vector(1 downto 0);
特點(FEATURES) 精確度0.1%滿刻度 (Accuracy 0.1%F.S.) 可作各式數(shù)學(xué)演算式功能如:A+B/A-B/AxB/A/B/A&B(Hi or Lo)/|A| (Math functioA+B/A-B/AxB/A/B/A&B(Hi&Lo)/|A|/etc.....) 16 BIT 類比輸出功能(16 bit DAC isolating analog output function) 輸入/輸出1/輸出2絕緣耐壓2仟伏特/1分鐘(Dielectric strength 2KVac/1min. (input/output1/output2/power)) 寬范圍交直流兩用電源設(shè)計(Wide input range for auxiliary power) 尺寸小,穩(wěn)定性高(Dimension small and High stability)