intdroduce talk - 11 mins
OOP - inheritance encapsulation - 15-20 mins
exact question longest substring non repeating - https://leetcode.com/problems/longest-substring-without-repeating-characters/ - 30 mins
only got O(n2) O(n2)… waffled for the last 7ish mins on improving O(n2) memory to O(n)…
class Solution {
public int lengthOfLongestSubstring(String s) {
int n = s.length();
int max = 0;
for(int i=0; i<n; i++){
HashSet<Character> set = new HashSet<Character>();
int count = 0;
for(int j=i; j<n; j++){
if(set.contains(s.charAt(j))){
break;
}else{
set.add(s.charAt(j));
count++;
if(count>max){
max = count;
}
}
}
}
return max;
}
}