C新手，求下面代码为何编译通不过

#include <stdio.h>
#define IN 1 /* inside a word */
#define OUT 0 /* outside a word */
/* count lines, words, and characters in input */
int main(void)
{
int c, nl, nw, nc, state;
state = OUT;
nl = nw = nc = 0;
while ((c = getchar()) != EOF)
{
++nc;
if (c == '\n')
++nl;
if (c == ' '|| c == '\n' || c = '\t')
state = OUT;
else if (state == OUT)
{
state = IN;
++nw;
}
}
printf("%d %d %d\n", nl, nw, nc);
getch();
}