1624. Largest Substring Between Two Equal Characters LeetCode Solution
In this guide, you will get 1624. Largest Substring Between Two Equal Characters LeetCode Solution with the best time and space complexity. The solution to Largest Substring Between Two Equal Characters problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.
Problem Statement of Largest Substring Between Two Equal Characters
Given a string s, return the length of the longest substring between two equal characters, excluding the two characters. If there is no such substring return -1.
A substring is a contiguous sequence of characters within a string.
Example 1:
Input: s = “aa”
Output: 0
Explanation: The optimal substring here is an empty substring between the two ‘a’s.
Example 2:
Input: s = “abca”
Output: 2
Explanation: The optimal substring here is “bc”.
Example 3:
Input: s = “cbzxy”
Output: -1
Explanation: There are no characters that appear twice in s.
Constraints:
1 <= s.length <= 300
s contains only lowercase English letters.
Complexity Analysis
Time Complexity: O(n)
Space Complexity: O(1)
1624. Largest Substring Between Two Equal Characters LeetCode Solution in C++
class Solution {
public:
int maxLengthBetweenEqualCharacters(string s) {
int ans = -1;
vector<int> lastSeen(26, -1);
for (int i = 0; i < s.length(); ++i) {
const int c = s[i] - 'a';
if (lastSeen[c] == -1)
lastSeen[c] = i;
else
ans = max(ans, i - lastSeen[c] - 1);
}
return ans;
}
}; /* code provided by PROGIEZ */
1624. Largest Substring Between Two Equal Characters LeetCode Solution in Java
class Solution {
public int maxLengthBetweenEqualCharacters(String s) {
int ans = -1;
int[] lastSeen = new int[26];
Arrays.fill(lastSeen, -1);
for (int i = 0; i < s.length(); ++i) {
final int c = s.charAt(i) - 'a';
if (lastSeen[c] == -1)
lastSeen[c] = i;
else
ans = Math.max(ans, i - lastSeen[c] - 1);
}
return ans;
}
} // code provided by PROGIEZ
1624. Largest Substring Between Two Equal Characters LeetCode Solution in Python
class Solution:
def maxLengthBetweenEqualCharacters(self, s: str) -> int:
ans = -1
lastSeen = {}
for i, c in enumerate(s):
if c not in lastSeen:
lastSeen[c] = i
else:
ans = max(ans, i - lastSeen[c] - 1)
return ans # code by PROGIEZ
