上述getword函数不能正确处理下划线、字符串常量、注释及预处理器控制指令。请编写一个更完善的getword函数

#include <stdio.h>
#include <ctype.h>

#define MAX_KEY 11
#define MAX_LEN 100
#define WORD 1

struct key
{
char *word;
int count;
} keytab[MAX_KEY] =
{
{“auto”, 0},
{“break”, 0},
{“case”, 0},
{“char”, 0},
{“const”, 0},
{“continue”, 0},
{“default”, 0},
{“unsigned”, 0},
{“void”, 0},
{“volatile”,},
{“while”, 0},
};

int state;

enum
{
CONST = 0X01,
SAID1 = 0X02,
SAID2 = 0X04,
FIRST = 0X08,

};

int getword(char *word, int max_len);
void state_deal(int type);
int binsearch(char *word);

main()
{
char word[MAX_LEN];
int type;
int n;

while ((type = getword(word, MAX_LEN)) != EOF)
{
	state_deal(type);
	if (state == 0 && type == WORD)
		if ((n = binsearch(word)) != EOF)
			keytab[n].count++;
}

for (n = 0; n < MAX_KEY; n++)
{
	if (keytab[n].count)
		printf("%s:\t%d\n", keytab[n].word, keytab[n].count);
}
return 0;

}

int getch(void);
void ungetch(int c);

int getword(char *word, int max_len)
{
int c, i = 0;

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while ((c = getch()) == ' ' || c == '\t');
if (!isalpha(c) && c != '_')
	return c;
while (isalnum(c) || c == '_')
{
	word[i++] = c;
	c = getch();
}
word[i] = '\0';

if (c != EOF)
	ungetch(c);
return WORD;

}

#define MAX_BUFF 100
char buff[MAX_BUFF];
int buffp;

int getch(void)
{
return buffp > 0 ? buff[–buffp] : getchar();
}
void ungetch(int c)
{
if (buffp < MAX_BUFF)
buff[buffp++] = c;
else
printf(“ungetch: the buff is full!\n”);
}

void state_deal(int type)
{
static int marks, c;

if ((state & (SAID1 | SAID2 | FIRST)) == 0 && type == '\"')
	marks++;

if (marks % 2 != 0)
	state |= CONST;
else
	state &= ~CONST;

if ((state & CONST) == 0 && c == '/' && type == '/')
	state |= SAID1;
if ((state & SAID1) && type == '\n')
	state &= ~SAID1;

if ((state & CONST) == 0 && c == '/' && type == '*')
	state |= SAID2;
if ((state & SAID2) && c == '*' && type == '/')
	state &= ~SAID2;

if (type == '#')
	state |= FIRST;
if ((state & FIRST) && type == '\n')
	state &= ~FIRST;	

c = type;

}

int binsearch(char *word)
{
int cond;
int low, high, mid;

low		= 0;
high	= MAX_KEY - 1;

while (low <= high)
{
	mid = (low + high) / 2;
	if ((cond = strcmp(word, keytab[mid].word)) > 0)
		low = mid + 1;
	else if (cond < 0)
		high = mid - 1;
	else
		return mid;
}

return EOF;

}