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：
1 #include <iostream>
2 #include <stdio.h>
3 using namespace std;
4
5 int main()
6 {
7 int i,j,n;
8 cin>>n;
9 getchar();
10 for(i=1;i<=n;i++){
11 char a[110];
12 cin.getline(a,110,'
');
13 if(('a'<=a[0] && a[0]<='z') || ('A'<=a[0] && a[0]<='Z') || a[0]=='_'){
14 for(j=0;a[j];j++)
15 if(!(('a'<=a[j] && a[j]<='z') ||
16 ('A'<=a[j] && a[j]<='Z') ||
17 ('0'<=a[j] && a[j]<='9') ||
18 a[j]=='_') )
19 break;
20 if(a[j])
21 cout<<"No"<<endl;
22 else
23 cout<<"Yes"<<endl;
24 }
25 else
26 cout<<"No"<<endl;
27 }
28 return 0;
29 }
30
31 /**************************************
32 Problem id : SDUT OJ 2163
33 User name : Miracle
34 Result : Accepted
35 Take Memory : 452K
36 Take Time : 0MS
37 Submit Time : 2014-04-20 09:18:49
38 **************************************/
Freecode : www.cnblogs.com/yym2013