#include <stdio.h>

__code state_0(char* s);
__code state_1(char* s);
__code state_2(char* s);
__code state_3(char* s);
__code accept(char* s);
__code reject(char* s);

int main(int argc, char* argv[]) {
	puts("regexp: (A|B)*C");
	puts("number of state: 4");
	printf("string: %s\n", argv[1]);
	goto state_1(argv[1]);

	return 0;
}

__code state_0(char* s) {
	switch(s++) {
		case '\0': 
			goto accept(s);
		default:
			goto reject(NULL);
	}
}

__code state_1(char* s) {
	switch(s++) {
		case 'A': 
			goto state_3(s);
		case 'C': 
			goto state_0(s);
		case 'B': 
			goto state_2(s);
		default:
			goto reject(NULL);
	}
}

__code state_2(char* s) {
	switch(s++) {
		case 'A': 
			goto state_3(s);
		case 'C': 
			goto state_0(s);
		case 'B': 
			goto state_2(s);
		default:
			goto reject(NULL);
	}
}

__code state_3(char* s) {
	switch(s++) {
		case 'A': 
			goto state_3(s);
		case 'C': 
			goto state_0(s);
		case 'B': 
			goto state_2(s);
		default:
			goto reject(NULL);
	}
}


__code accept(char* s) {
	printf("\nstring matches regexp. \n\n");
}

__code reject(char* s) {
	printf("\nstring does not match regexp. \n\n");
}