2. 将实数写入文件:从键盘输入若干实数(以特殊数值-1结束),分别写到一个文本文件中。试编写相应程序。#includestdio.h #includestdlib.h int main(){ double num; FILE *fpfopen(f4.txt,w); if(fpNULL){ printf(File can not open\n); exit(0); } scanf(%lf,num); while(num!-1){ fprintf(fp,%.2f ,num); scanf(%lf,num); } if(fclose(fp)){ printf(Can not close the file!\n); exit(0); } return 0; }