力扣第3题，无重复最长子串

Question

class Solution {
public:
int lengthOfLongestSubstring(string s) {
   if(s=="")
    return 0; 
int n=s.size();
int start,end=0;
int maxLength=0;
unordered_set<char>Lookfor;
while(end<n){
    char cur=s[end];
    if(!Lookfor.count(cur)){
   Lookfor.insert(cur);
   maxLength=max(maxLength,end-start+1);
        end++;
    }
   else{
    Lookfor.erase(s[start]);
    start++;
   }
}
return maxLength;
    }
};

为什么会报错越界，把 Lookfor.insert(cur);
maxLength=max(maxLength,end-start+1);这两行换下顺序就可执行不是很理解

Answer 1

貌似start没有赋予初始值0 啊
int start=0,end=0; 试试呢