3. Longest Substring Without Repeating Characters

Given a string, find the length of the longest substring without repeating characters.

Examples:

Given "abcabcbb", the answer is "abc", which the length is 3.

Given "bbbbb", the answer is "b", with the length of 1.

Given "pwwkew", the answer is "wke", with the length of 3. Note that the answer must be a substring, "pwke" is a subsequenceand not a substring.

class Solution {public:    int lengthOfLongestSubstring(string s) {         set<char> substring;        int size=s.length();        int *p=new int[size];        int count=0;        for(int i=0;i<size;i++)        {        for(int j=i;j<size;j++)        {        if(substring.find(s[j])!=substring.end())        {        break;        }         else        {                    substring.insert(s[j]);        count++;        }        }        p[i]=count;        substring.clear();        count=0;        }        count=0;        for(int i=0;i<size;i++)        {        if(p[i]>count) count=p[i];        }        return count;    }};