sdut 2163:Identifiers（第二届山东省省赛原题，水题）

Identifiers

Time Limit: 1000ms   Memory limit: 65536K  有疑问？点这里^_^

题目描述

 Identifier is an important concept in the C programming language. Identifiers provide names for several language elements, such as functions, variables, labels, etc.

An identifier is a sequence of characters. A valid identifier can contain only upper and lower case alphabetic characters, underscore and digits, and must begin with an alphabetic character or an underscore. Given a list of chararcter sequences, write a program to check if they are valid identifiers.

输入

 The first line of the input contains one integer, N, indicating the number of strings in the input. N lines follow, each of which contains at least one and no more than 100 characters. (only upper and lower case alphabetic characters, digits, underscore (" "), hyphen ("-"), period ("."), comma (","), colon (":"), semicolon (";"), exclamation mark ("!"), question mark ("?"), single and double quotation marks, parentheses, white space and square brackets may appear in the character sequences.)

输出

For each of the N lines, output "Yes" (without quote marks) if the character sequence contained in that line make a valid identifier; output "No" (without quote marks) otherwise.

示例输入

7
ValidIdentifier
valid_identifier
valid_identifier
0_invalid_identifier
1234567
invalid identifier
adefhklmruvwxyz12356790_-.,:;!?'"()[]ABCDGIJLMQRSTVWXYZ

示例输出

Yes
Yes
Yes
No
No
No
No

提示

 

来源

山东省第二届ACM大学生程序设计竞赛

---

 

　　水题。

　　代码：

 #include <iostream>
 #include <stdio.h>
 using namespace std;

 int main()
 {
     int i,j,n;
     cin>>n;
     getchar();
     for(i=;i<=n;i++){
         char a[];
         cin.getline(a,,'\n');
         if(('a'<=a[] && a[]<='z') || ('A'<=a[] && a[]<='Z') || a[]=='_'){
             for(j=;a[j];j++)
                 if(!(('a'<=a[j] && a[j]<='z') ||
                      ('A'<=a[j] && a[j]<='Z') ||
                      (''<=a[j] && a[j]<='') ||
                      a[j]=='_') )
                      break;
             if(a[j])
                 cout<<"No"<<endl;
             else
                 cout<<"Yes"<<endl;
         }
         else
             cout<<"No"<<endl;
     }
     return ;
 }

 /**************************************
     Problem id    : SDUT OJ 2163
     User name    : Miracle
     Result        : Accepted
     Take Memory    : 452K
     Take Time    : 0MS
     Submit Time    : 2014-04-20 09:18:49
 **************************************/

Freecode : www.cnblogs.com/yym2013