从第m个数开始复制字符串

指针法

#include<stdio.h>
#include<string.h>
void copystr(char *a,char *b,int m)
{
 a=a+m-1;
 while(*a!="")
 {
  *b=*a;
  b++;
  a++;
 }
 *b="";
}
int main()
{
 char a[100],b[100];
 int m;
 gets(a);
 printf("which character begin to copy?");
 scanf("%d",&m);
 if(strlen(a)<m||strlen(a)<0)
 printf("error");
 else
 copystr(a,b,m);
 puts(b);
 return 0;
}

数组法

#include<stdio.h>
#include<string.h>
void copystr(char a[100],char b[100],int m)
{
 
 int i;
 for(i=0;a[i]!="";i++)
 b[i]=a[i+m-1];
 b[i]="";
}
int main()
{
 int m;
 char a[100],b[100];
 gets(a);
 printf("which character that begin to copy?");
 scanf("%d",&m);
 if(strlen(a)<m||strlen(a)<0)
 printf("error");
 else
 copystr(a,b,m);
 printf("result=%s
",b);
 return 0;
}