字符過濾【二】有順序的過濾重複字符

#include <stdio.h>

typedef struct tagFilterChar
{
	int ch;
	int n;
}FilterChar;

void insert_sort(FilterChar* arr,int n) 
{ 
	int i,j; 
	FilterChar temp = {0}; 
	for(i = 1;i < n; i++) 
	{ 
		temp = *(arr + i); 
		for(j = i; j > 0 && (arr + j - 1)->n > temp.n; j--) 
		{ 
			*(arr + j) = *(arr + j - 1); 
		} 
		*(arr + j) = temp;
	} 
} 
void filterchar(const char* src, char* dst)
{
	const char* p = NULL;
	int ch = 0;
	FilterChar flag[0xff] = {0};
	int i = 0;
	int num = 0;
	if (src == NULL || dst == NULL)
		return ;
	p = src;
	while (ch = *p++)
	{
		if (!flag[ch].ch)
		{
			flag[ch].ch = ch;
			flag[ch].n = num++;
		}
	}
	insert_sort(flag,0xff);
	for (i = 0; i < 0xff; ++i)
	{
		if (flag[i].ch)
			*dst++ = flag[i].ch;
	}
	*dst = 0;
}
int main(void)
{
	int n = 0;
	char arr[100];
	filterchar("..,dcbadcba,",arr);
	puts(arr);
	return 0;
}