[BNUZOJ1261][ACM][2016北理校赛]方块消除(栈,字符串)

package bnuzoj1261;

import java.util.Scanner;

public class Main {

    public static void run( String str ) {

        StringBuffer sb = new StringBuffer();
        char[] chs = str.toCharArray();
        sb.append( chs[ 0 ] );
        for( int i = 1; i < str.length(); ) {
            if(sb.length() < 1){
                sb.append( chs[i] );
                i++;
            }
            else if( chs[ i ] != sb.charAt( sb.length()-1 ) ) {
                sb.append( chs[i] );
                i++;
            } else {
                if( chs[i] == sb.charAt( sb.length()-1 )){
                    do{
                        i++;
                    }while(i<chs.length && chs[i] ==sb.charAt( sb.length()-1 ));
                 sb.delete(sb.length()-1,sb.length());
                }
            }
        }
        System.out.println( sb.toString() );
    }

    public static void main( String[] args ) {
        Scanner sc = new Scanner( System.in );
        int T = sc.nextInt();

        while( T-- > 0 ) {
            String str = sc.next();
            run( str );
        }
    }

}