USACO 1.2 Namenum

题目连接

http://train.usaco.org/usacoprob2?a=7LsqvWoYMNU&S=namenum

Description

Among the large Wisconsin cattle ranchers, it is customary to brand cows with serial numbers to please the Accounting Department. The cow hands don’t appreciate the advantage of this filing system, though, and wish to call the members of their herd by a pleasing name rather than saying, “C’mon, #4734, get along.”

Help the poor cowhands out by writing a program that will translate the brand serial number of a cow into possible names uniquely associated with that serial number. Since the cow hands all have cellular saddle phones these days, use the standard Touch-Tone(R) telephone keypad mapping to get from numbers to letters (except for “Q” and “Z”):

      2: A,B,C     5: J,K,L    8: T,U,V
      3: D,E,F     6: M,N,O    9: W,X,Y
      4: G,H,I     7: P,R,S

Acceptable names for cattle are provided to you in a file named “dict.txt”, which contains a list of fewer than 5,000 acceptable cattle names (all letters capitalized). Take a cow’s brand number and report which of all the possible words to which that number maps are in the given dictionary which is supplied as dict.txt in the grading environment (and is sorted into ascending order).

For instance, the brand number 4734 produces all the following names:

GPDG GPDH GPDI GPEG GPEH GPEI GPFG GPFH GPFI GRDG GRDH GRDI
GREG GREH GREI GRFG GRFH GRFI GSDG GSDH GSDI GSEG GSEH GSEI
GSFG GSFH GSFI HPDG HPDH HPDI HPEG HPEH HPEI HPFG HPFH HPFI
HRDG HRDH HRDI HREG HREH HREI HRFG HRFH HRFI HSDG HSDH HSDI
HSEG HSEH HSEI HSFG HSFH HSFI IPDG IPDH IPDI IPEG IPEH IPEI
IPFG IPFH IPFI IRDG IRDH IRDI IREG IREH IREI IRFG IRFH IRFI
ISDG ISDH ISDI ISEG ISEH ISEI ISFG ISFH ISFI
As it happens, the only one of these 81 names that is in the list of valid names is “GREG”.

Write a program that is given the brand number of a cow and prints all the valid names that can be generated from that brand number or ``NONE’’ if there are no valid names. Serial numbers can be as many as a dozen digits long.

Input

A single line with a number from 1 through 12 digits in length.

Output

A list of valid names that can be generated from the input, one per line, in ascending alphabetical order.

Sample Input

4734

Sample Output

GREG

题意

牛之间用手机进行练习,给出牛的名单表和手机按键,判断这个牛是否在名单表中。

题解

很容易知道按照输入来枚举的话数量很爆炸,所以直接按读入文件来进行枚举,转换后和输入相同就输出它就可以了。本题在另一方面练习了文件流的读写。

代码

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/*
ID: hyson601
PROG: namenum
LANG: C++11
*/
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
const char alpha[26]={'2','2','2','3','3','3','4','4',
'4','5','5','5', '6','6','6','7',
'0','7','7','8','8','8','9','9','9','0'};
string words,tmp,data;
bool flag;
int main(){
//定向程序IO。
ifstream fin("namenum.in");
ofstream fout("namenum.out");
//不进行数字操作,只进行比较操作,直接用string处理。
fin>>data;
//定向名字文件IO。
ifstream tin("dict.txt");
while(tin>>words){
//获取当前单词长度,再分开判断。
int wnum=words.size();
tmp="";
for(int i=0;i<wnum;++i)
tmp+=alpha[words[i]-65];
if(tmp==data){
fout<<words<<endl;
flag=true;
}
}
if(!flag) fout<<"NONE"<<endl;
return 0;
}