练习1-12 编写一个程序，以每行一个单词的形式打印其输入。

#include <stdio.h>
#define IN  1
#define OUT 0

int main()
{
    int c, state;
    state = OUT;

    while( (c = getchar()) != EOF)

    {
        if(c == ' ' || c == '\n' || c == '\t')
        {
            if(state == IN)
            {
                putchar('\n');
                state = OUT;
              }
         }
        else if (state == OUT)
        {
            state = IN;
            putchar(c);
        }
        else
       putchar(c);

    }
}