char find_first(char *arr,int len)
{
int asg[256] = {0};
for (int i = 0; i < len; i++)
{
asg[(int)arr[i]]++;
}
for (int i = 0; i < len; i++)
{
if (asg[(int )arr[i]] == 1)
return arr[i];
}
}
int main()
{
char*str = "aaaaaaaccdeefddddfffffffff6";
char ret=find_first(str,strlen(str));
printf("%c",ret);
system("pause");
}