LeetCode-3. Longest Substring Without Repeating Characters

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问题描述

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

Example 1:

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

Constraints:

  • 0 <= s.length <= 5 * 104
  • s consists of English letters, digits, symbols and spaces.

解答

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/*
 * @Description: 3. Longest Substring Without Repeating Characters
 * @Author: libk
 * @Github: https://github.com/libk
 */
/**
 * @param {string} s
 * @return {number}
 */
const lengthOfLongestSubstring = function (s) {
  const hashTable = {}
  let start = -1
  let maxLen = 0

  for (let end = 0; end < s.length; end++) {
    let cur = hashTable[s[end]]
    if (cur !== undefined && cur > start) { // 如果遇见重复的字符，且重复的字符在窗口之内
      start = cur
    }
    hashTable[s[end]] = end
    maxLen = maxLen > (end - start) ? maxLen : end - start
  }
  return maxLen
}