Sliding Window: Return he longest length of the substring with consecutive characters

Coding Interview Questions

1 min read

Problem Statement:

Return he longest length of the substring with consecutive characters.

Example:

Input: Input: sdfdsioweabcdef

Output: 6

Explanation: "abcdef" is the length of continuous alphabetical substring

Solution Explanation:

We will solve the problem with the help of sliding window approach.

We will check if s[i+1]-s[i] is 1, then update the length.

Else reset the length to 1 and string the window.

Time Complexity: O(n)
Space Complexity: O(1)

Code Solution

#include <iostream>
#include <vector>
#include <string>
using namespace std;

int solution(string s) 
{
    int n = s.size();
    int result = 1;
    int length = 1;

    int left = 0;
    for(int right = 0 ; right <n ;)
    {
        if(s[right+1]-s[right] == 1)
        {
            length ++;
            result = max(result, length);
        }
        else
        {
            length = 1; 
            left++;
        }
        right++;
    }
    return result;
}

int main()
{

    string str = "sdfdsioweabcdef";
    cout << solution(str);
}