//bat7.java
import java.io.*;
import java.util.*;
class bat7 extends c2java {
   public static void main(String xxx[]){
      bat7 me = new bat7( );
      //me.prepareIO( );   // cin, cout, cerr
      me.main( );
   }
   bat7( ) {   // constructor
      //super( );  // invoke super class's constructor
   }
   bat7(BufferedReader gg, PrintStream yy) { 
         // this constructor is for network version
      cin = gg;
      cout = yy;
      cerr = yy;
   }
////////
//bat6ok.c  -- @CopyLeft by tsaiwn@csie.nctu.edu.tw
//BATtle of NUMbers
//modified by __學號__  _姓_名_  and  __學號__  _姓_名_ 
///
// 若用 Java 則須用 class 包起來; class名稱須與檔案名稱相同 !
// 且 main 必須 public static void main(String xxx[ ]) {
//#define repeat  do {
//#define until(x)   } while(! (x) )

//#include <stdio.h>
//#include <stdlib.h>
//#include <time.h>

//#define MAX_STONE 31
 public final static int MAX_STONE = 31;
 public final static int MIN_STONE = 18;
 public final static int MAX_TAKE = 9;
//#define MIN_STONE 18
//#define MAX_TAKE 9

//Java 內以上須用這樣 public final static int MAX_TAKE = 9;

//#ifndef __cplusplus
  //typedef enum {false=0, true } bool; // C 不認識 這些
//#endif

// define some global variables for the Game
int nStone; // number of Stone
int maxTake; // max stone to take for some game

int lastToWin;  // Win or Lose if took last one stone?
// 因為用來做 array[lastToWin] 所以改用 int
boolean userFirst, playAgain;
/// 
enum player {USER, COMPUTER};  // 這樣寫後面可以用USER/COMPUTER
player who; // who is taking the stone? 輪到誰?
  // Java 的 enum 請看本檔案最後的補充 ! 
//void hello( ), prepareGame( ), playGame( );
//bool askUserFirst( ), askPlayAgain( );
//void userTurn( ), computerTurn( );
//void randomize( ) { srand(time(0));  } // 抓時間來當作亂數種子

   
//////
int main( ) {
   hello( ); 
//   randomize( );  // randomize; make it true random
   //repeat
   do {
      prepareGame( );
      userFirst = askUserFirst( );
      playGame( );
      playAgain = askPlayAgain( );
   }while (playAgain);
   //until( ! playAgain );
   printf("Thank you for your play.\r\n");
   return 0;
}

void hello( ) {  
   printf("Welcome to the BATNUM game ...\r\n");
}

void prepareGame( ) {
   //char msg[ ][88]={"Lose the game.", "win the game."};
   String msg[ ]={"Lose the game.", "win the game."};
   nStone = MIN_STONE + rand( ) % (MAX_STONE-MIN_STONE+1);
   maxTake = 3 + rand( ) % (MAX_TAKE -3 +1);  // 3..
   lastToWin = rand( )%2 ;  // half chance 一半的機會  ******
   printf("\r\nThere are %d stones.\r\n", nStone);
   printf("At least take 1, at most %d stones.\r\n", maxTake);
   printf("The one who take the last stone will ");
   printf("%s\r\n", msg[lastToWin]); // 拿最後一個輸還是贏?
//#ifdef DEBUG
   //printf("lastToWin=%d\n", lastToWin);
//#endif
} // prepareGame

boolean askUserFirst( ) {
   //static char buf[99];
   String buf;
   //fprintf(stderr, "Do you want to go first(Y, N)? ");
   printf("Do you want to go first(Y, N)? ");
   //fgets(buf, sizeof(buf), stdin);
   buf = fgets( );
   //if(buf[0]==0) return false;  // no!  C不認識 true/false
   if(buf==null) return false;
   if(buf.equals("")) return false;
   //if(buf[0]=='N' || buf[0]=='n') return false; //no
   if(buf.charAt(0)=='N' || buf.charAt(0)=='n') return false;
   return true;  //  Yes otherwise
}
boolean askPlayAgain( ) {
   //static char buf[99];
   String buf;
   //fprintf(stderr, " Play again(Y, N)? ");
   printf( " Play again(Y, N)? ");
   //fgets(buf, sizeof(buf), stdin);
   buf = fgets( );
   //if(feof(stdin)) return false;  // EOF encounted
   if(buf==null) return false;
   if(buf.equals("")) return false;
   //if(buf[0]=='N' || buf[0]=='n') return false; //no
   if(buf.charAt(0)=='N' || buf.charAt(0)=='n') return false;
   return true;  // Yes
} // askPlayAgain

void playGame( ) {
   boolean userWin=true; // assume user win
   if(userFirst) userTurn( );
   else printf(" OK. I go first.\r\n");
   while(nStone > 0 ) {
      computerTurn( );
      if(nStone <= 0) break; // gameOver
      userTurn( );
   } // game Over when leave the while Loop
   userWin = true; // assume you win
   if((lastToWin==1) && (who == player.COMPUTER) ) userWin = false; // user 輸!
   if( (lastToWin==0) && (who == player.USER) ) userWin = false; // user 也是輸
   // ******* 注意  lastToWin 現在是 int
   if(userWin) printf(" Congratulations! You win!\r\n");
   else printf(" Sorry, I won! Ha ha!\n");
} // playGame

void userTurn( ) { 
   int nTake, canTake;
   //static char buf[99];
   String buf;
   who = player.USER;  // now USER 's turn  記住輪到 USER
   canTake = maxTake;  // 照規定最多只能拿取 maxTake
   if(nStone < maxTake) canTake = nStone;  // 沒那麼多了
   printf(" How many you want to take(1..%d)? ", canTake);
   //fgets(buf, sizeof(buf), stdin);
   buf = fgets( );
   nTake = (int)atol(buf);  
   // check if the nTake is legal ?
   // .. 若不符規定則要求 USER 重新輸入
   // .. 也可寫成若輸入負數表示 give up, 就結束此 game :-(
   while(nTake < 1 || nTake > canTake) { // illegal
      printf("  ?? Error, please re-type(1..%d)? ", canTake);
      //fgets(buf, sizeof(buf), stdin);
      buf = fgets( );
      nTake = (int)atol(buf);  
   }
   nStone -= nTake;
   if(nStone == 0) printf(" You just took the last stone.\r\n");
   else printf(" %d stone(s) left.\r\n", nStone);
   return;
} // userTurn

void computerTurn( ) {
   int nTake = 1;
   who = player.COMPUTER;  // now is COMPUTER 's turn 記住輪到 COMPUTER
   // 必贏的策略?  須考慮拿最後一個贏還是輸
   nTake = nStone;
   if(lastToWin == 0) nTake--;  // 拿最後一個是輸ㄝ, 留一個給對手
   nTake = nTake % (1+maxTake);
   if(nTake == 0) nTake = 1; // 電腦會輸, 先賴皮拿一個等對手拿錯:-)
   if(nTake > nStone) nTake = nStone; // 沒那麼多! (不可能發生)
  ///
   nStone -= nTake;  // 拿走啊
   printf(" I take %d stone", nTake);
   if(nTake > 1) printf("s");  // 複數
   printf(" this time.");
   if(nStone == 0) printf(" I just took the last stone.\r\n");
   else printf(" Now %d stone(s) left.\r\n", nStone);
} // computerTurn
///   === === END of the program BATNUM === ===

} //class