Problem
Given a string, find the length of the longest substring without repeating characters.
Examples:
Given "abcabcbb"
, the answer is "abc"
, which the length is 3.
Given "bbbbb"
, the answer is "b"
, with the length of 1.
Given "pwwkew"
, 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.
Solution
/**
* @param {string} s
* @return {number}
*/
var lengthOfLongestSubstring = function(s) {
var map = {};
var len = s.length;
var max = 0;
var start = 0;
for (var i = 0; i < len; i++) {
if (map[s[i]] !== undefined) {
start = Math.max(start, map[s[i]] + 1);
}
map[s[i]] = i;
max = Math.max(max, i - start + 1);
}
return max;
};
Explain:
nope.
Complexity:
- Time complexity : O(n).
- Space complexity : O(n).