poj 2105 IP Address(水题)

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一、Description

Suppose you are reading byte streams from any device, representing IP addresses. Your task is to convert a 32 characters long sequence of '1s' and '0s' (bits) to a dotted decimal format. A dotted decimal format for an IP address is form by grouping 8 bits at a time and converting the binary representation to decimal representation. Any 8 bits is a valid part of an IP address. To convert binary numbers to decimal numbers remember that both are positional numerical systems, where the first 8 positions of the binary systems are:

2⁷   2⁶  2⁵  2⁴  2³   2²  2¹  2⁰ 128 64  32  16  8   4   2   1

Input

The input will have a number N (1<=N<=9) in its first line representing the number of streams to convert. N lines will follow.

Output

The output must have N lines with a doted decimal IP address. A dotted decimal IP address is formed by grouping 8 bit at the time and converting the binary representation to decimal representation.
二、题解
今天见鬼了，碰到这么多水题。这题就是在采用什么读取输入流时纠结了一下，最后还是用了SC,然后再用字符串的性质解决了问题。
三、java代码

import java.util.Scanner;public class Main {public static int transform(String s){int sum=0;if(s.charAt(0)=='1')sum+=128;if(s.charAt(1)=='1')sum+=64;if(s.charAt(2)=='1')sum+=32;if(s.charAt(3)=='1')sum+=16;if(s.charAt(4)=='1')sum+=8;if(s.charAt(5)=='1')sum+=4;if(s.charAt(6)=='1')sum+=2;if(s.charAt(7)=='1')sum+=1;return sum;}     public static void main(String[] args) {     Scanner sc=new Scanner(System.in);    int n,i;    String s;    n=sc.nextInt();    for(i=0;i<n;i++){    s=sc.next();    System.out.println(transform(s.substring(0,8))+"."+transform(s.substring(8,16))+"."    +transform(s.substring(16,24))+"."+transform(s.substring(24,32)));    }        }}