[求助]关于while ( *p2++=*(p1+n-1)++);,
											为什么错了,书上说这是交简单方法、但我用上却不对
#include<stdio.h>
#include<string.h>
  void main()
  { void copystr(char * p1,char *p2,int n );
    int m;
    char str1[20]={0},str2[20];
    printf("\n inpurt string one :\n");
    gets(str1);
    printf("which character that begin to copy:\n" );
    scanf("%d",&m);
    if (strlen(str1)<m)
      {
    printf("Input characters are not enough ,please input again!\n");
     gets(str1);
      }
      else
      {
    copystr(str1,str2,m);
    printf("result: %s\n",str2);
       }
   }
   void copystr(char *p1,char *p2,int n)
   {
     while ( *p2++=*(p1+n-1)++);
}

 
											





 
	    