In this post, we are going to solve the Longest Substring Without Repeating Characters Leetcode Solution problem of Leetcode. This Leetcode problem is done in many programming languages like C++, Java, and Python.
Problem
Given a string s, find the length of the longest substring 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.
Constraints
0 <= s.length <= 5 * 104sconsists of English letters, digits, symbols and spaces.
Longest Substring Without Repeating Characters Leetcode Solution in Python
class Solution:
def lengthOfLongestSubstring(self, s):
start = maxLength = 0
usedChar = {}
for i in range(len(s)):
if s[i] in usedChar and start <= usedChar[s[i]]:
start = usedChar[s[i]] + 1
else:
maxLength = max(maxLength, i - start + 1)
usedChar[s[i]] = i
return maxLengthLongest Substring Without Repeating Characters Leetcode Solution in CPP
class Solution {
public:
int lengthOfLongestSubstring(string s) {
int n = s.length(), longest = 0;
vector<int> nextIndex(128);
for (int r=0, l=0; r<n; r++) {
l = max(nextIndex[s[r]], l);
longest = max(longest, r - l + 1);
nextIndex[s[r]] = r + 1;
}
return longest;
}
};Longest Substring Without Repeating Characters Leetcode Solution in Java
class Solution {
public int lengthOfLongestSubstring(String s) {
int n = s.length(), longest = 0;
int[] nextIndex = new int[128];
for (int r=0, l=0; r<n; r++) {
l = Math.max(nextIndex[s.charAt(r)], l);
longest = Math.max(longest, r - l + 1);
nextIndex[s.charAt(r)] = r + 1;
}
return longest;
}
}Note: This problem Longest Substring Without Repeating Characters is generated by Leetcode but the solution is provided by Chase2learn This tutorial is only for Educational and Learning purposes.
