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!='\0') {  *b=*a;  b++;  a++; } *b='\0';}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]!='\0';i++) b[i]=a[i+m-1]; b[i]='\0';}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\n",b); return 0;}