字符串中第一个只出现一次的字符

#include <iostream>   
#include <assert.h>
using namespace std;  

int findFisrtUniqueChar(const char *str, char &ch)
{
	assert(str != NULL);
	unsigned int m=strlen(str);
	unsigned int i;
	unsigned int anCount[256];
	memset(anCount, 0, sizeof(unsigned int) *256 );
	for (i=0; i<m; i++)
	{
		anCount[(unsigned char)str[i]]++;
	}

	for (i=0; i<m; i++)
	{
		if (anCount[(unsigned char)str[i]] == 1)
		{
			ch= str[i];
			return 0;
		}
	}

	ch='\0';
	return -1;
}

int main()  
{  
	char *str1 = "afaccde";  
	char *str2="abaccdeff";
	char *str3="abcdefggfedcba";
	char ch;
	if (findFisrtUniqueChar(str1,ch) == 0)
	{
		cout<<"The first Unique char in "<<str1<<" is:  "<<ch<<endl;
	}
	else
	{
		cout<<str1<<"  contains  no unique char"<<endl;
	}

	cout<<endl;
	if (findFisrtUniqueChar(str2,ch) == 0)
	{
		cout<<"The first Unique char in "<<str2<<" is:  "<<ch<<endl;
	}
	else
	{
		cout<<str2<<"  contains  no unique char"<<endl;
	}

	cout<<endl;
	if (findFisrtUniqueChar(str3,ch) == 0)
	{
		cout<<"The first Unique char in "<<str3<<" is:  "<<ch<<endl;
	}
	else
	{
		cout<<str3<<"  contains  no unique char"<<endl;
	}
	
	return 0;  
}