对下面程序描述正确的是( )。 #include #include void main() {FILE *in,*out; if((in=fopen("file1.txt","a+"))==NULL) {printf("cannot open file1\n"); exit(0); }if((out=fopen("file2.txt","a+"))==NULL)
对下面程序描述正确的是( )。 #include #include void main() {FILE *in,*out; if((in=fopen("file1.txt","a+"))==NULL) {printf("cannot open file1\n"); exit(0); }if((out=fopen("file2.txt","a+"))==NU