你准备如何测试单词计数程序?如果程序中存在某种错误，那么什么样的输入最可能发现这类错误呢？（书中单词定义较宽松，是不含空格，制表符，换行符的连续字符序列）
#include <stdio.h>
#define IN 1 /* inside a word */
#define OUT 0 /* outside a word */
/* count lines, words, and characters in input */ main()
{
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); }
究竟有什么错误啊，根本看不出来。
