Give My Text Back

Give My Text Back

标签（空格分隔）： 算法

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时间限制:10000ms

单点时限:1000ms

内存限制:256MB

描述

To prepare for the English exam Little Ho collected many digital reading materials. Unfortunately the materials are messed up by a malware.

It is known that the original text contains only English letters (a-zA-Z), spaces, commas, periods and newlines, conforming to the following format:

1. Each sentence contains at least one word, begins with a letter and ends with a period.

2. In a sentence the only capitalized letter is the first letter.

3. In a sentence the words are separated by a single space or a comma and a space.

4. The sentences are separated by a single space or a single newline.

It is also known the malware changes the text in the following ways:

1. Changing the cases of letters.

2. Adding spaces between words and punctuations.

Given the messed text, can you help Little Ho restore the original text?

输入

A string containing no more than 8192 English letters (a-zA-Z), spaces, commas, periods and newlines which is the messed text.

输出

The original text.

样例输入

my Name is Little Hi.

His name IS Little ho , We are friends.

样例输出

My name is little hi.

His name is little ho, we are friends.

解析

规则：

1. 每个标点符号之前没有空格，标点符号之后加空格；
2. ‘.’之后表示每个句子的开始，首字母应该大写；
3. 只有每个句子的句首字母应该大写；

代码：

import java.util.Scanner;
public class Main {
    public static String dealwith(String s) {
	    String s1 = s.trim().toLowerCase();
	    char[] ch = s1.toCharArray();
	    ch[0] = Character.toUpperCase(ch[0]);
	    StringBuffer sb = new StringBuffer();
    	boolean flag = false;
	    for(int i=0; i<ch.length; i++) {
	    	if( ch[i] <= 'z' && ch[i] >= 'A') { //正常的字符
		    	if(flag == true) {
			    	sb.append(Character.toUpperCase(ch[i]));
				    flag = false;
			    }
			else
				sb.append(ch[i]);
		}
		else if(ch[i] == ' ') { //如果是空格，分两种情况
			if(sb.charAt(sb.length()-1) != ' ')
				sb.append(" ");
			else
				continue;
		}
		else { //是标点符号
			if(ch[i] == '.')
				flag = true;
			if(sb.charAt(sb.length()-1) == ' ') { //如果标点前有空格，则删除
				sb.deleteCharAt(sb.length()-1);
				sb.append(ch[i]);
				sb.append(" ");
			}
			else {
				if(i == ch.length-1) //如果是最后一个字符
					sb.append(ch[i]);
				else {
					sb.append(ch[i]);
					sb.append(" ");
				}
			}
		}

	}
	return sb.toString();
}

public static void main(String[] args) {
	// TODO Auto-generated method stub
	Scanner sc = new Scanner(System.in);
	while(sc.hasNext()) {
		String s = sc.nextLine();
		String res = dealwith(s);
		System.out.println(res);
	}
}

}