假定名为“test.txt"的文本文件不存在。写出下列程序的输出结果。
#include"stdio.h"
main()
{FILE*fp;
char*s[3]={"12","abc","789");
intk:
if((fp=fopen("test.txt","a+"))==NULL)
{printf("Filenotopen!\n");exit(0);}
for(k=0;k%3;k++)fwrite(s[k],(10ng)(k+1),1,fp);
rewind(fp);
while(!feof(fp))printf("%c",fgetc(fp));
fclose(fp);
}