C++,

time: O(n^2)

space: O(0)

class Solution {public:    /**     * @param str: a string     * @return: a boolean     */    bool isUnique(string &str) {        // write your code here        for (int i=0; i

C++,

time: O(n)

space: O(n)

1 class Solution { 2 public: 3     /** 4      * @param str: a string 5      * @return: a boolean 6      */ 7     bool isUnique(string &str) { 8         // write your code here 9         string tmp;10         for (int i=0; i