ht.c

#include <stdio.h>
#include <stdlib.h>

#define c1(c) ((((c) << 1) & 0x2a) | (((c) >> 1) & 0x15))	// 交换
#define c2(c) ((c) >> 6)	// 循环左移位数
#define c3(c) ((c1((c)) >> 6 - c2((c))) | ((c1((c)) << c2((c))) & 0x3f) | ((c) & 0xc0))	//循环

void encode(char *s);

int main(void)
{
	char instr[200];
	puts("input a string:");
	gets(instr);
	encode(instr);
	puts(instr);
	return 0;
}

void encode(char *s)
{
	int i = 0;
	while(s[i] != '\0')
		s[i++] = (c3(s[i]));
}