Given a string s, find the length of the longestsubstring without repeating characters.
Example 1:
Input: s = "abcabcbb"
Output: 3
Explanation: The answer is "abc", with the length of 3.
Example 2:
Input: s = "bbbbb"
Output: 1
Explanation: The answer is "b", with the length of 1.
Example 3:
Input: s = "pwwkew"
Output: 3
Explanation: The answer is "wke", with the length of 3.
Notice that the answer must be a substring, "pwke" is a subsequence and not a substring.
Pseudocode
- iterate through string to add into a Set, using two pointers
- one to iterate through loop
- one as a trailing pointer to delete all letters in the set when repeated letters are found
- if letter found to be repeating/not unique
- delete trailing letters using a second pointer in a while loop
- increment pointer until all letters are deleted
- repeated letter is added into set in the following sequence
- if letter is unique
- add into set
- set size = longest unique substring
- use Math.max() to book keep
Solution
// https://leetcode.com/problems/longest-substring-without-repeating-characters/
var lengthOfLongestSubstring = function (s) {
let maxLength = 0;
let set = new Set();
let left = 0;
for (let i = 0; i < s.length; i++) {
let curr = s[i];
while (set.has(curr)) {
set.delete(s[left]);
left++;
}
set.add(curr);
maxLength = Math.max(maxLength, set.size);
}
return maxLength;
};
