#include void main() { FILE *fp; int n,sum=0; if((fp=fopen(\ printf(\ while(!feof(fp)) { fscanf(fp,\ sum+=n; } fprintf(fp,\ fclose(fp); } 3.
#include #include
void main(int argc,char *argv[ ]) { FILE *in,*out; char ch; if (argc!=3) { printf(\ exit(0); } if((in=fopen(argv[1],\ { printf(\ exit(0); } if((out=fopen(argv[2],\ { printf(\ exit(0); } while(!feof(in)) fputc(fgetc(in),out); fclose(in); fclose(out); } 4.
#include #include void main() { FILE *fp; int n,a=0,b=0,c=0; if((fp=fopen(\ printf(\ while(!feof(fp)) { fscanf(fp,\ if(n>0) a++; else if(n<0) b++; else c++; } printf(\正数有%d个，负数有%d个，零有%d个\\n\ fclose(fp); }