简单文件处理C程序时出错

Here's the code:

这是代码:

#include<stdio.h>
int main()
{
    FILE *fp;
    int i;
    fp=fopen("DATA","w");
    for(i=1;i<=30;++i)
        putw(i,fp);
    fclose(fp);
    fp=fopen("DATA","r");
    while((i=getw(fp))!=EOF)
        printf("%4d",i);
    fclose(fp);
    return 0;
}
#include<stdio.h>
in