C # I/O Assistant class

when using C # To solve ACM problems, it is easier to read integers directly from the standard input using a readint32 method. The following is an I/O Assistant class iohelper:

Namespace skyiv {using system; using system. IO; using system. Text; sealed class iohelper: idisposable {static readonly encoding = encoding. ASCII; // or utf8? Static readonly byte [] eols = encoding. getbytes (environment. newline); static readonly byte [] blanks = {9, 10, 13, 32}; // tab, lf, Cr, space static readonly byte EOF = 0; // assume '\ 0' not in input file byte [] Buf = new byte [32]; // For write (int n) byte [] buffer = new byte [64*1024]; int current = 0; int COUNT = 0; binaryreader reader; binarywriter writer; Public iohelper (): This (console. openst Andardinput (), console. openstandardoutput () {} public iohelper (Stream reader, stream writer) {This. reader = new binaryreader (Reader); this. writer = new binarywriter (writer);} byte readbyte () {If (current> = count) {COUNT = reader. read (buffer, current = 0, buffer. length); If (COUNT = 0) return EOF;} return buffer [current ++];} public static byte [] getbytes (string Str) {return encoding. getby TES (STR) ;}public int readint32 () {var n = 0; var OK = false; For (byte B; (B = readbyte ())! = EOF;) {If (array. indexof (blanks, B)> = 0) if (OK) break; else continue; n = N * 10 + (B-'0'); OK = true ;} return N;} public int Readline (byte [] buffer) {var n = 0; while (n <buffer. length) {var B = readbyte (); If (B = eols [0]) {If (eols. length = 2 & readbyte ()! = Eols [1]) throw new invaliddataexception ("invalid EOL"); break;} buffer [n ++] = B;} return N;} public void write (INT N) {If (n = 0) {writer. write (byte) '0'); return;} var I = Buf. length; For (; n> 0; N/= 10) BUF [-- I] = (byte) (n % 10) + '0'); write (BUF, i, Buf. length-I);} public void write (byte [] buffer, int index, int count) {writer. write (buffer, index, count);} public void write (Str Ing Str) {var buffer = encoding. getbytes (STR); writer. write (buffer, 0, buffer. length);} public void writespace () {writer. write (blanks, 3, 1);} public void writeline () {writer. write (eols, 0, eols. length);} public void dispose () {If (reader! = NULL) reader. Close (); If (writer! = NULL) writer. Close ();}}}

The iohelper class also provides the following methods for processing strings:

• Public int Readline (byte [] buffer)
• Public void write (byte [] buffer, int index, int count)

Similar to C/C ++, these two methods only process strings as byte arrays and use ASCII codes. Rather than using Unicode as a string in C.

The following is a usage example. For the source of the question, see the essay "I-keyboard.

Namespace skyiv. ben. ACM {using system; // http://www.spoj.pl/problems/IKEYB/ sealed class ikeyb {const int max = 90; static int [,] cost = new int [Max + 1, Max + 1]; static int [,] Price = new int [Max + 1, Max + 1]; static int [,] Index = new int [Max + 1, Max + 1]; static int [] f = new int [Max]; static byte [] keys = new byte [Max]; static byte [] letters = new byte [Max]; static byte [] message1 = iohelper. getbytes ("keypad #"); static byte [] message2 = iohelper. getbytes (":"); static iohelper helper; static void main () {using (helper = new iohelper () {var runner = new ikeyb (); var T = helper. readint32 (); For (VAR n = 1; n <= T; n ++) runner. run (n) ;}} void run (int n) {var K = helper. readint32 (); var L = helper. readint32 (); helper. readline (KEYS); helper. readline (letters); For (VAR I = 0; I <L; I ++) f [I] = helper. readint32 (); initialize (K, L); compute (K, L); helper. write (message1, 0, message1.length); helper. write (n); helper. write (message2, 0, 1); helper. writeline (); output (K, L); helper. writeline ();} void initialize (int K, int L) {for (VAR I = 0; I <= K; I ++) for (VAR j = 1; j <= L; j ++) price [I, j] = int. maxvalue/2; for (VAR I = 1; I <= L; I ++) for (var j = I; j <= L; j ++) cost [I, j] = cost [I, j-1] + (J-I + 1) * f [J-1];} void compute (int K, int L) {for (VAR I = 1; I <= K; I ++) for (var j = I; j <= L; j ++) for (VAR n = 1; n <= J-I + 1; n ++) {var sum = Price [I-1, J-N] + cost [J-n + 1, J]; if (sum <= Price [I, j]) {price [I, j] = sum; index [I, j] = n ;}} void output (int K, int L) {If (k = 0) return; var n = index [k --, l]; output (K, L-N); helper. write (keys, k, 1); helper. write (message2, 0, message2.length); helper. write (letters, L-N, N); helper. writeline ();}}}

If the following input is provided:

 
12 5 * # abcde1024327682147483647987654321
 

AboveProgramThe following output is generated:

 
Keypad #1: *: ABCD #: E
 

Note that the above output is actually incorrect. Correct output should be divided into AB and cde groups. However, there is no problem with the program itself, but there is a problem with the input data. Because the frequency of each letter in the original question cannot exceed 100000.