删除小写字母字符串中重复字符。

删除小写字母字符串中重复字符。比如，输入：bbcacdww；输出：bacdw。

void DeleteString(char* pstr){if (pstr == NULL)return;//创建哈希表并初始化char *pHash = pstr;const int tablesize = 256;int hashtable[tablesize];for (int idx = 0; idx < tablesize; ++idx)hashtable[idx] = 0;//统计每个字符出现的次数while (*pHash != '\0')hashtable[*(pHash++)]++;pHash = pstr;int k = 0;while (*pHash != '\0'){if (hashtable[*pHash]){pstr[k++] = *pHash;pHash++;if (hashtable[*pHash] > 1)pHash++;}}pstr[k] = 0;}