Longest Substring Without Repeating Characters

Question

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

Example 1

Input: "abcabcbb"

Output: 3 (The longest substring without repeating characters is "abc")

Solution

▭

all//Longest Substring Without Repeating Characters.py

def longestSubstring(s):
    st = 0
    maxLen = 0
    start = 0
    usedChar = {}

    for i in range(len(s)):
        if s[i] in usedChar and st <= usedChar[s[i]]:
            st = usedChar[s[i]]
        else:
            maxLen = max(maxLen, i - st + 1)

        usedChar[s[i]] = i

    return maxLen

print(longestSubstring("abccdefgh"))

▯

all//Longest Substring Without Repeating Characters.py

def longestSubstring(s):
    st = 0
    maxLen = 0
    start = 0
    usedChar = {}

    for i in range(len(s)):
        if s[i] in usedChar and st <= usedChar[s[i]]:
            st = usedChar[s[i]]
        else:
            maxLen = max(maxLen, i - st + 1)

        usedChar[s[i]] = i

    return maxLen

print(longestSubstring("abccdefgh"))