题目是去掉源文件中的注释  // ....    /* ....  */

#include <stdio.h>
#include <stdlib.h>
void main()
{
    FILE *fin,*fout;
    char ch,pre;
    char resource[256],target[256];
    printf("请输入源文件名:\n");
    scanf("%s",resource);
        if((fin=fopen(resource,"r"))==NULL)
    {
        printf("打开源文件出错:\n");
        exit(0);
    }

    printf("请输入目标文件名:\n");
    scanf("%s",target);


    if((fout=fopen(target,"w"))==NULL)
    {
        printf("打开目标文件出错:\n");
            exit(0);
    }

    while(!feof(fin))
    {
        ch=fgetc(fin);
        if(ch=='/')
        {   pre=ch;
            ch=fgetc(fin);
            if(ch=='/')
            {   
                while(ch!='/n')
                    ch=fgetc(fin);
                fputc(ch,fout);
            }
            else if(ch=='*')
            {
                pre=fgetc(fin);
                ch=fgetc(fin);
                while(pre!='*'&&ch!='*')
                    ch=fgetc(fin),pre=ch;
            }
            else
               fputc(pre,fout);
               fputc(ch,fout);
        }
        else
            fputc(ch,fout);
    }
    fclose(fin);
    fclose(fout);
}编译成功后运行，输入目标文件按回车后 一直等待 ，生成文件为空 。

else if(ch=='*')
            {
                pre=fgetc(fin);
                ch=fgetc(fin);
                while(pre!='*' && ch!='/')
                    ch=fgetc(fin),pre=ch;    // ch取文件下一个字符，然后将ch值赋予pre   那while循环判断的不是两个相同的字符吗？
                ch=fgetc(fin),pre=ch;
            }
这段代码有问题，