将一个字符串,左旋N个字符

#include "stdio.h"


size_t _strlen(char* str)
{
	if (str==NULL || *str=='\0') return 0;

	int count=0;
	while (*str++)
	{
		count++;
	}
	return count;
}
void scroll_str(char* str,int step)
{
	if (str==NULL || *str=='\0' || step<=0) return;
	int len=_strlen(str);
	int real_step=step%(len-1);
	
	char c=*str;
	char* p1=str;
	char* p2=str+1;
	for (int i=0;i


算法待优化