Convert an unsigned integer back to char*?

Question

I have a hash function which returns back to me an unsigned integer uint32_t given a char* as shown below:

uint32_t key_hashing(const char* key)
{
    return hashing(key, 0x7fffffff, 101);
}

uint32_t hashing(const char* word, int tsize, uint32_t seed)
{
    char c;
    uint32_t h = seed;
    for ( ; (c=*word) != '\0'; ++word)
    {
        h ^= ( (h<<5) + c + (h >> 2) );
    }
    return ((uint32_t)(h&0x7fffffff) % tsize);
}

Now I want to do opposite: Let's say I have been given uint32_t number, I want to revert back to its original form which was in char* earlier. How can I do that? Basically my uint32_t number should give me back the original char* that was passed.

Answer 1

由于哈希冲突，这种方法行不通：字节数组可以有任意多种排列，但只有固定数量的不同uint32_t ，因此一堆不同的char *将哈希到相同的 uint32_t值。