Find只出现一次的元素

void FindNumOfOne(char str[]){int i,len;if (str == NULL)return;len = strlen(str);const int tableSize = 256;unsigned int hash[tableSize];for (i = 0; i < tableSize; i++){hash[i] = 0;}for (i = 0; i < len; i++){hash[str[i] - '0']++;}for (i = 0; i < len; i++){if (hash[str[i] - '0'] == 1){cout << str[i] << endl;break;}}}