> #include<iostream>
> #include<ctype.h>
> using namespace std;
> 
> const int error=9;
> 
> int f(int s,char input)
> {
> 	switch(s)
> 	{
> 	case 0:
> 		{
> 			if(isdigit(input)) return 2;
> 			if(input=='+'||input=='-') return 1;
> 			if(input=='\0') return 8;
> 			break;
> 		}
> 	case 1:
> 		{
> 			if(isdigit(input)) return 2;
> 			break;
> 		}
> 	case 2:
> 		{
> 			if(isdigit(input)) return 2;
> 			if(input=='.') return 3;
> 			if(input=='e'||input=='E') return 5;
> 			if(input=='\0') return 8;
> 			break;
> 		}
> 	case 3:
> 		{
> 			if(isdigit(input)) return 4;
> 			break;
> 		}
> 	case 4:
> 		{
> 			if(isdigit(input)) return 4;
> 			if(input=='e'||input=='E') return 5;
> 			if(input=='\0') return 8;
> 			break;
> 		}
> 	case 5:
> 		{
> 			if(isdigit(input)) return 7;
> 			if(input=='+'||input=='-') return 6;
> 			break;
> 		}
> 	case 6:
> 		{
> 			if(isdigit(input)) return 7;
> 			break;
> 		}
> 	case 7:
> 		{
> 			if(isdigit(input)) return 7;
> 			if(input=='\0') return 8;
> 			break;
> 		}
> 	}
> 	return error;
> }
> char *p;
> 
> char get()
> {
> 	p++;
> 	return *(p-1);
> }
> 
> int main()
> {
> 	const int maxn=1100;
> 	char a[maxn];
> 	int s,t;
> 	scanf("%d\n",&t);
> 	while(t--)
> 	{
> 		cin.getline(a,maxn);
> 		for(p=a;*p;p++);
> 		for(;p>=a&&*(p-1)==' ';p--);
> 		*p='\0';
> 		for(p=a;*p==' ';p++);
> 		s=0;
> 		while((s=f(s,get()))!=8&&s!=error);
> 		if(s==8) printf("LEGAL\n");
> 		else printf("ILLEGAL\n");
> 	}
> 	return 0;
> }

我的DFA怎么就WA呢
T_T