GCJ 2011 - Magicka

Magicka.java

import java.util.*;
import java.io.*;

public class Magicka {
  public String castAspell(HashMap<String, String> mergeMap, HashMap<String, ArrayList<String>> opposingMap, 
                                    String invokeString, int invokeStringLength) {
    StringBuilder sbOutput = new StringBuilder("" + invokeString.charAt(0));

    for(int i=1;i<invokeStringLength;i++) {
      int len = sbOutput.length();
      if(len > 0) {
        int pos = sbOutput.length() - 1;
        String str1 = "" + sbOutput.charAt(pos);
        String str2 = "" + invokeString.charAt(i);

        if(mergeMap.containsKey(str1+str2) || mergeMap.containsKey(str2+str1)) {     
        sbOutput.deleteCharAt(pos);
        sbOutput.append(mergeMap.get(str1+str2));
        continue;
      } else {
        String tempStr = sbOutput.toString();
        Iterator iter = opposingMap.entrySet().iterator();
        boolean flag = false;

        while (iter.hasNext()) {
          Map.Entry pair = (Map.Entry) iter.next();
          String key = (String) pair.getKey();
          ArrayList&ltString&gt keyList = (ArrayList<String>) pair.getValue();
      
          if(tempStr.indexOf(key) >= 0) {
            for(String value: keyList) {
              if(str2.indexOf(value) >= 0) {
                sbOutput.delete(0, len);
                flag = true;
              }
            }
          }

          if(flag) {
            break;
          }
        }
     
        if(!flag) {
          sbOutput.append(", " + invokeString.charAt(i));
        }
      }
    } else {
      sbOutput.append(invokeString.charAt(i));
    }
  }

  return "[" + sbOutput.toString() + "]";
 }
}