HDOJ/HDU 2163 Palindromes(判断回文串~)

Problem Description

Write a program to determine whether a word is a palindrome. A palindrome is a sequence of characters that is identical to the string when the characters are placed in reverse order. For example, the following strings are palindromes: “ABCCBA”, “A”, and “AMA”. The following strings are not palindromes: “HELLO”, “ABAB” and “PPA”.

Input

The input file will consist of up to 100 lines, where each line contains at least 1 and at most 52 characters. Your program should stop processing the input when the input string equals “STOP”. You may assume that input file consists of exclusively uppercase letters; no lowercase letters, punctuation marks, digits, or whitespace will be included within each word.

Output

A single line of output should be generated for each string. The line should include “#”, followed by the problem number, followed by a colon and a space, followed by the string “YES” or “NO”.

Sample Input

ABCCBA

A

HELLO

ABAB

AMA

ABAB

PPA

STOP

Sample Output

#1: YES
#2: YES
#3: NO
#4: NO
#5: YES
#6: NO
#7: NO

就是简单的判断回文串的问题，遇到STOP结束程序。

import java.util.Scanner;

/**
 * @author 陈浩翔
 * 2016-6-5
 */
public class Main{

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int t =1;
        while(sc.hasNext()){
            String str =sc.next();
            if("STOP".equals(str)){
                return;
            }
            System.out.print("#"+(t++)+": ");
            boolean isProgram = true;
            for(int i=0,j=str.length()-1;i<j;i++,j--){
                if(str.charAt(i)!=str.charAt(j)){
                    isProgram=false;
                    break;
                }
            }
            if(isProgram){
                System.out.println("YES");
            }else{
                System.out.println("NO");
            }

        }
    }
}