### 003 Longest Substring Without Repeating Characters

```/**
*
* Ashish Patel
* e: ashishsushilPatel@gmail.com
* w: https://ashish.me
*
*/

/*
Given a string, find the length of the longest substring without repeating characters.

Example 1:

Input: "abcabcbb"
Output: 3
Explanation: The answer is "abc", with the length of 3.
Example 2:

Input: "bbbbb"
Output: 1
Explanation: The answer is "b", with the length of 1.
Example 3:

Input: "pwwkew"
Output: 3
Explanation: The answer is "wke", with the length of 3.
Note that the answer must be a substring, "pwke" is a subsequence and not a substring.
*/
function longestSubstringWithoutRepeatingCharacters(value) {
let windowChars = {} // {a: 0, b: 1, c: 2}
let windowStart = 0
let maxCount = 0
for (let index = 0; index < value.length; index++) {
const endChar = value[index];
if(windowChars[endChar] >= windowStart){
windowStart = windowChars[endChar] + 1
}
windowChars[endChar] = index
maxCount = Math.max(maxCount, index - windowStart +  1)
}
return maxCount
}

test('longest Substring Without Repeating Characters', () => {
expect(longestSubstringWithoutRepeatingCharacters('abcabcbb')).toEqual(3)
});```

Created 2020-02-23T08:56:10+00:00, updated 2020-02-23T16:58:11+00:00 · History · Edit