#include <fstream.h>
#include <string.h>

typedef char	lexunit[12];
enum lexeme {REC, PROG, PROC, FUNC, FOR, WHILE, REPEAT, THEN, ELSE, DO, 
				BEGIN, UNTIL, END1, END2, END3, JUNK};
void Search (char [], lexunit [], lexeme &);

int main ()
{
	lexunit		keys[] = {"record", "program", "procedure", "function", "for", "while", 
							"repeat", "then", "else", "do", "begin", "until", 
							"end", "end;",  "end."};
	lexeme		stack[50];
	int			top = -1;
	lexeme		where;
	int			ahead;
	char		word[60];
	char		filename[30];
	ifstream	input;

	cout << "File to analyze: ";
	cin >> filename;
	input.open(filename);
	input >> word;
	while (input)
	{
		ahead = 0;
		Search (word, keys, where);
		if (where < JUNK)
		{
			if (where < DO) 
			{
				top++;
				stack[top] = where;
				if (where != REC)
					cout << ' ' << (int)where;
				if (where == REPEAT)
					cout << 'B';
			}
			if (where == THEN || where == ELSE || where == DO)
			{
				input >> word;
				ahead = 1;
				if (strcmp(word,keys[(int)BEGIN]) != 0)
					top--;
			}
			if (where == BEGIN)
				cout << 'B';
			if (where >= UNTIL)
			{
				if (stack[top] != REC)
					cout << ' '  << (int)stack[top]  << 'E';
				top--;
			}
		}
		if (!ahead) 
			input >> word;
	}
	input.close();
	cout << endl;
	return 0;
}

void Search (char  word[],  lexunit  keys[], lexeme &where)
{
	int		j = 0;
	int		count = (int)JUNK;

	while (j < count && strcmp(word, keys[j]) != 0)
		j++;
	where = (lexeme) j;
}