first single char

#include <iostream>
using namespace std;

//first single char 
char firstSingle(char *str){
	int a[255];//char 0-255
	memset(a,0,sizeof(int)*255);
	char *p = str;
	while (*p != '\0')
	{
		a[*p]++;
		p++;
	}
	p = str;
	while (*p != '\0')
	{
		if (a[*p] == 1)
		{
			return *p;
		}
		p++;
	}
	return '\0';
}

int main(void){
	char a[] = "abacfeds";
	cout<<a<<endl;
	char ch = firstSingle(a);
	cout<<"single char:"<<ch;
	system("pause");
	return 0;
}