PAT 1073

简单题，字符串处理，写的有点乱

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

class FastReader{
    BufferedReader reader;
    StringTokenizer tokenizer;
    
    public FastReader(InputStream stream){
        reader = new BufferedReader(new InputStreamReader(stream), 1 << 22);
        tokenizer = null;
    }
    
    public String next(){
        while (tokenizer == null || !tokenizer.hasMoreTokens()){
            try { 
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (Exception e){
                //System.out.println(-1);
                throw new RuntimeException(e);
            }
        }
        
        return tokenizer.nextToken();
    }
    
    public int next_int(){
        return Integer.parseInt(next());
    }
    
    public float next_float(){
        return Float.parseFloat(next());
    }
}

public class Main {
    public static void main(String[] args){
        FastReader reader = new FastReader(System.in);
        String input = reader.next();
        
        int num_sig = (input.charAt(0) == '+') ? 1 : -1;
        String int_part = input.substring(1, 2);
        
        String dec_part;
        int cur_idx = 3;
        while (Character.isDigit(input.charAt(cur_idx)))
            cur_idx++;
        
        dec_part = input.substring(3, cur_idx);
        
        cur_idx++;
        int exp_num = Integer.parseInt(input.substring(cur_idx));
        
        
        int dec_part_cnt = dec_part.length();
        
        StringBuilder res_sb = new StringBuilder();
        
        if (exp_num < 0){
            exp_num = -exp_num;
            
            if (num_sig == -1)
                res_sb.append('-');
            
            res_sb.append("0.");
            exp_num--;
            while (exp_num != 0){
                res_sb.append('0');
                exp_num--;
            }
            
            res_sb.append(int_part);
            res_sb.append(dec_part);
        } else {
            if (num_sig == -1)
                res_sb.append('-');
            
            if (exp_num >= dec_part_cnt){
                res_sb.append(int_part);
                res_sb.append(dec_part);
                
                int zero_cnt = exp_num - dec_part_cnt;
                for (int i = 0; i < zero_cnt; i++)
                    res_sb.append('0');
            } else {
                res_sb.append(int_part);
                res_sb.append(dec_part.substring(0, exp_num));
                res_sb.append('.');
                res_sb.append(dec_part.substring(exp_num));
            }
        }
        
        System.out.println(res_sb.toString());
    }
}