lengthOfLongestSubstring.cpp

//
// Created by zhangxh on 2019-09-08.
//
int lengthOfLongestSubstring(string s) {
    int max=0;
    string subs=s.substr(0,1);
    if(s.size()==1) return 1;
    for(int i =1;i<s.size();++i){
        auto pos=subs.find(s[i]);
        if (pos==-1) {subs.append(s,i,1);continue;}
        max=(subs.size()>max)? subs.size():max;
        subs.erase(0,pos+1);
        subs.append(s,i,1);
    }
    max=(subs.size()>max)? subs.size():max;
    return max;
    }