|
单词符号 |
种别码 |
单词符号 |
种别码 |
|
begin |
1 |
: |
17 |
|
if |
2 |
:= |
18 |
|
then |
3 |
< |
20 |
|
while |
4 |
<= |
21 |
|
do |
5 |
<> |
22 |
|
end |
6 |
> |
23 |
|
l(l|d)* |
10 |
>= |
24 |
|
dd* |
11 |
= |
25 |
|
+ |
13 |
; |
26 |
|
- |
14 |
( |
27 |
|
* |
15 |
) |
28 |
|
/ |
16 |
# |
0 |
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
|
用文法描述词法规则：<BR><字母>->a/b/c.../z<BR><数字>->1/2/3/4/5/6/7/8/9<BR><标识符>->sum.....<BR><关键字>->begin/if/then/while/do/end<BR><运算符>->+,-,*,/,:,:=,<,<=,<>,>,>=,=<BR><界符>->;|(|)|[|]|{|}<BR>已完成的代码如下：<BR>#include<stdio.h> #include<stdlib.h> #include<string.h> char word[6][5]={"begin","if","then","while","do","end"}; char word2[18][3]={"|","dd*","+","-","*","/",":",":=","<","<=","<>",">",">=","=",";","(",")","#"}; int words(char ch[][5]); int signs(char ch[][3]); main() { char ch[10]; printf("请输入保留字："); scanf("%s",ch); words(ch); signs(ch); } int words(char ch[][5]) { while(ch==''||ch==10||ch==13||ch==9) { getchar; } if(ch>='a'&&ch<='z') { switch(ch)<BR> {}<BR> } } int signs(char ch[][3]) { while(ch==''||ch==10||ch==13||ch==9) { getchar; } if(ch>='0'&&ch<='9') { switch(ch)<BR> {} } } |