ECNU-2574 Principles of Compiler

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <stdlib.h>
 4 const int maxn = 205;
 5 
 6 int pos;
 7 int len;
 8 char a[ maxn ];
 9 
10 bool solveA();
11 bool solveB();
12 bool solveC();
13 
14 bool solveA(){
15     //printf("A:%c\n",a[pos]);
16     //if( pos>=len ) return false;
17     if( a[pos]==‘(‘ ){
18         pos++;
19         if( solveB() ){
20             if( a[pos]==‘)‘ ){
21                 pos++;/*该字符后面可能还有字符*/
22                 return true;
23             }
24             else{
25                 return false;
26             }
27         }
28         else 
29             return false;
30     }
31     else
32         if( a[pos]==‘x‘ ){
33             pos++;
34             return true;
35         }
36     else{
37         pos++;/*同理，该字符后面可能还有字符*/
38         return false;
39     }
40 }
41 
42 bool solveB(){
43     //printf("B:%c\n",a[pos]);
44     if( solveA() ){
45         return solveC();
46     }
47     else return false;
48 }
49 
50 
51 bool solveC(){
52     if( pos>=len ) return false;
53     while( pos<len && a[pos]==‘+‘ ){
54         pos++;
55         solveA();
56     }
57     return true;
58 }
59 
60 
61 int main(){
62     int T;
63     scanf("%d",&T);
64     while( T-- ){
65         memset( a,‘\0‘,sizeof( a ) );
66         scanf("%s",a);
67         pos = 0;
68         len = strlen( a );
69         bool f = solveA();
70         if( pos<len ) {printf("Bad\n");continue;}
71         /*防止出现前半部分符合条件，后半部分不合的用例*/
72         if( f ) printf("Good\n");
73         else printf("Bad\n");
74     }
75     return 0;
76 }