剑指Offer33 第一个只出现一次的字符

/*************************************************************************
    > File Name: 33_FirstNotRepeatChar.c
    > Author: Juntaran
    > Mail: JuntaranMail@gmail.com
    > Created Time: 2016年09月02日 星期五 13时43分20秒
 ************************************************************************/

#include <stdio.h>

char FirstNotRepeatChar(char* str)
{
    if (str == NULL)
        return '\0';
    int HashSize = 256;
    int hash[HashSize] = {0};
    
    char* key = str;
    while (*key != '\0')
    {
        printf("*key = %d\n", *key);
        hash[*key] ++;
        *key ++;
    }
    
    key = str;
    while (*key != '\0')
    {
        printf("%d ", hash[*key]);
        if (hash[*key] == 1)
            return *key;
        key ++;
    }
    return '\0';
}

int main()
{
    char str[] = "adaccbweff";
    char ret = FirstNotRepeatChar(str);
    printf("%c\n", ret);
}