简单的输入输出

#include<stdio.h>void main(){int n,a,i,sum;FILE *fin,*fout;if((fin=fopen("in.txt","r"))==NULL){printf("Input file open error!\n");return;}if((fout=fopen("out.txt","w"))==NULL){printf("Output file open error!\n");return;}while(!feof(fin)){fscanf(fin,"%d ",&n);for(i=0,sum=0;i<n;i++){fscanf(fin,"%d",&a);sum+=a;}fprintf(fout,"%d\n",sum);}fclose(fin);fclose(fout);}