Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length is 3. For "bbbbb" the longest substring is "b", with the length of 1.

Longest Substring Without Repeating Characters.cpp

class Solution {
public:
    int lengthOfLongestSubstring(string s) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        unsigned int result = 0;
        set<char> table;
        queue<char> substr;
        for(int i = 0; i < s.length(); ++i) {
            if(table.find(s[i]) != table.end()) {
                while(substr.front() != s[i]) {
                    table.erase(substr.front());
                    substr.pop();
                }
                substr.pop();
            } else {
                table.insert(s[i]);
            }
            
            substr.push(s[i]);
            
            result = max(result, substr.size());
        }
        
        return result;
        
    }
};