Example: Input: str = "abcc", K = 2 Output: 2 Explanation: Possible substrings of length K = 2 are ab : 2 distinct characters bc : 2 distinct characters cc : 1 distinct character Only two valid subst Nov 13, 2023 · Find distinct characters in distinct substrings of a string; Maximum consecutive occurrences of a string in another given string; Count of distinct characters in a substring by given range for Q queries; Count M-length substrings occurring exactly K times in a string; Count number of distinct substrings of a given length Aug 25, 2021 · Given a string str and a character K, the task is to find the count of all the substrings of str that contain the character K. Complete the ashtonString function in the editor below. Input format : The first line contains a string ‘str’. Implementation: Method 2 (Using substr () function): s. Keep a count of nodes that are being created in the Trie while inserting the substrings (suffixes). If count [x] is greater than 1, then ignore the repeated Apr 1, 2024 · F inding the longest substring with a specific number of distinct characters is a frequent task encountered in the realm of string manipulation. Traverse the input string str and do following for every character x = str [i]. 47% of Python3 online submissions for Substrings of Size Three with Distinct Characters. There will be n*(n+1)/2 substrings. ab : 2 distinct characters. Examples: Input: S = "ababcb", K = 3. Examples: There are 4 unique substrings. Count substrings made up of a single distinct character - In this article, we'll discuss the problem of counting the number of substrings in a given string that consist of a single distinct character. Traverse str using two for loops from i=0 to i<lenght and j=i to j<lenght. For example, consider string abcbdbdbbdcdabd. Output : 4. substr (i, len) prints substring of length ‘len’ starting from index i in string s. ) Auxiliary Space: O (1) May 28, 2024 · Given string str of the lowercase alphabet and an integer K, the task is to count all substrings of length K which have exactly K distinct characters. length(); int count Jun 9, 2021 · Selecting the character ‘X’ and removing the substrings “YZ” in two consecutive operations reduces the string to “XXX”, which consists of a single distinct character only. Substrings of Size Three with Distinct Characters - LeetCode Dec 28, 2022 · Given string str of the lowercase alphabet and an integer K, the task is to count all substrings of length K which have exactly K distinct characters. Function Description. All valid sub-strings are “a Substrings of Size Three with Distinct Characters - Level up your coding skills and quickly land a job. Iterate over the string and insert new characters in the HashMap until we have exactly K distinct characters in the HashMap. Mar 3, 2024 · Using itertools. the longest non-repeating substring output. One way is to define starting point, ending point and step size. Unlike subsequences, substrings are required to occupy consecutive positions within the original string. then the count of all contiguous substrings starting and ending with same character is n* (n+1)/2. Here’s an example: import itertools def distinct_substrings_itertools(s): return len(set(s[i:j] for i, j in itertools. We have explored 3 approaches to solve this. A string a a is a substring of a string b b if a a can be obtained from b b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters Aug 30, 2021 · The problem differs from the problem of finding the longest subsequence with k distinct characters. Repeat step 2 as many times as required. String getUniqueCharacterSubstring(String input) {. Input: S="efecfefd", K = 4. Take temp as count of unique elements in substring str [i Feb 27, 2021 · Your task is to return the count all the possible substrings that have exactly 'k' distinct characters. Traverse the input string again and do following for every character str [i] If count [x] is 1, then print the unique character. All the characters of the input string are lowercase alphabets. Creating substring of last n character is very much similar to creating substring of first n character with a little changes in syntax. combinations(range(len(s) + 1), 2 Given a string of lowercase alphabets, count all possible substrings (not necessarily distinct) that have exactly k distinct characters. Example 1: Input: S = "aba", K = 2 Output: 3 Explanation: The substrings are: "ab", "ba" and "aba". Example: Input: str = "abcc", K = 2 Output: 2 Explanation: Possible substrings of length K = 2 are ab : 2 distinct characters bc : 2 distinct characters cc : 1 distinct character Only two valid subst Aug 5, 2016 · 3. If we apply this brute force, it would take O (n 2) to generate all substrings May 27, 2017 · Given that your column is varchar, it means it can only store characters from codes 0 to 255, on whatever code page you have. Example: Input: str = “abcc”, K = 2. Note: even if some substrings coincide, count them as many times as they appear in the obtained string. Note: The string S consists of only lowercase English alphabets. All elements are not Distinct. Explanation: Splitting two strings as “abc” and “cba” has 3 distinct characters each. Naive approach A Enter the string: abcd Enter k value: 1 Total substrings with exactly 1 distinct characters : 4 Enter the string: mqtt Enter k value: 2 Total substrings with exactly 2 distinct characters : 3 Enter the string: aaaa Enter k value: 2 Total substrings with exactly 2 distinct characters : 0 Method 1 - Brute Force Count Complete Substrings - You are given a string word and an integer k. Examples: Input: N = 6, S = “abccba”. May 1, 2023 · If K = 5 then, the answer is b, the 5th character of the 1-indexed concatenated string. string x = s. Example 1: Input: s = "abcabc" Output: 10 Explanation: The substrings containing at least one occurrence of the characters a, b and c Apr 26, 2023 · Given a String, the task is to write a Python program to extract strings of N size and have K distinct characters. Output: Explanation: Only one valid substring exists {"cc"}. So remember Dec 6, 2021 · If dict object contains k+1 distinct characters, remove the leftmost character from dict and move the start_window to right. Output: -1. For example, given the string "aabac" and the parameters n=3 and k=2 , a desirable output would be ["aab", "aba", "bac"] . This is the best place to expand your knowledge and get prepared for your next interview. A substring is a contiguous subsegment of a string. At this point, we have a window (subarray) that conforms to our criteria of having exactly K unique characters. May 22, 2023 · Given a string, count all distinct substrings of the given string. eg:-string=ABBC. May 28, 2021 · Given a string S of size N consisting of characters a, b, and c only, the task is to find the number of substrings of the given string S such that the frequency of character a is greater than the frequency of character c. Nov 1, 2023 · Given a string S consisting of lower case alphabets of size N and Q queries in the range [L, R], the task is to print the count of distinct characters in the substring by given range for each query. Example 2: Input: s = "bbbbb" Output: 1 Explanation: The answer is "b", with the length of 1. “g”, “ge”, “gee”, “geek” and “geeks” are the valid substrings. Examples: Input: S = “geeksforgeeks”, Q [] [] = { {0, 4}, {3, 7}} Output: 4. Note that if there are multiple occurrences of the same substring, every occurrence should be counted. I need to find out count of such distinct SET made from substrings in a string. HashSet doesn't allow duplicated so you can first prepare a ArrayList having duplicate values and pass it to constructor of HashSet and get all duplicated removed. Output : 3. if string is aa, it’s distinct substrings are a and aa. Using this analogy, we can write solution with o (n^2) time complexity and constant space complexity. Examples: In Nov 11, 2023 · Example-2: Python substring containing last n characters. substr( 0 , i+1 ); Mar 3, 2021 · Count of all unique substrings with non-repeating characters; Find the number of strings formed using distinct characters of a given string; Count the number of times a letter appears in a text file in Python; Program to count occurrence of a given character in a string; Find the longest substring with k unique characters in a given string Jan 9, 2023 · Given a integer k and a string str, the task is to count the number of distinct sub-strings such that each sub-string does not contain some specific characters more than k times. Given a string str consisting of lowercase characters, the task is to find the total number of unique substrings with non-repeating characters. length <= 100; s consists of lowercase English letters. objects. Approach: The given problem can be solved using the set data structure. For example, a schematic diagram of the indices of the string 'foobar' would look like this: String Indices. String indexing in Python is zero-based: the first character in the string has index 0, the next has index 1, and so on. Runtime: 39 ms, faster than 43. Also string, apple contains only 4 distinct characters. ( I will refer the three a s as a1,a2 and a3 just to distinguish them). Find how many of its n(n+1) 2 n ( n + 1) 2 substrings are diverse. Output: 2. so that the sliding window contains again k distinct characters only. Problem Statement : Given a string of lowercase alphabets, count all possible substrings (not necessarily distinct) that has exactly k distinct characters. In case of multiple answers, print any one. Take the initial count as 0. Examples: Input: str = “ababab”, anotherStr = “bcd”, k = 1. For example, the underlined substrings in "computer" and "computation" only differ by the 'e'/'a', so this is a valid way. distinct character sets of substrings are:{A},{B},{C},{A,B},{A,B,C},{B,C} Jul 20, 2021 · The good substrings are “abc”, “bca”, “cab”, and “abc”. Substrings are often used for various text manipulation tasks, including searching, comparing, and extracting data. The pseudo code looks like this: string s; cin >> s; int sol = 0. The number of nodes in the Trie is the Jun 30, 2021 · Given n the length of the input string, we can solve the problem by testing all the substrings of length 3. For example, if the input string is “abcba”, n is 3, and k is 2, the expected output would be [“abc”, “bcb”, “cba”] since each of these substrings of length 3 has exactly 2 distinct characters. So, a string say, orange contains 6 distinct characters. Implementation: Method 3 (Generate a substring using the previous substring): Apr 15, 2024 · The input string is geeksforgeeks. name: Mar 5, 2024 · 💡 Problem Formulation: This article tackles the challenge of generating all possible substrings of length n that consist of exactly k distinct characters from a given string. The second line of the input is the string of characters " 0 " and " 1 ", the length is exactly 26 characters. Jan 5, 2021 · Function substring_k (string str, int length, int k) takes str and k and returns count of the number of substrings with exactly k distinct characters. Output : abcd abc ab a bcd bc b cd c d. Output: abc. and finally return count. if string is aa, it's distinct substrings are a and aa. Aug 17, 2023 · Longest substring having K distinct vowels; Count substrings made up of a single distinct character; Python – N sized substrings with K distinct characters; Count the number of vowels occurring in all the substrings of given string in C++; Count of all substrings with sum of weights at most K; Find distinct characters in distinct substrings Sep 18, 2023 · Replace minimal number of characters to make all characters pair wise distinct; Minimize length of string by replacing K pairs of distinct adjacent characters; Count substrings made up of a single distinct character; Check if a string can be split into two strings with same number of K-frequent characters; Reverse alternate k characters in a string Apr 4, 2023 · Out of the above substrings, there. 2. LeetCode Solutions in C++20, Java, Python, MySQL, and TypeScript. Example: Input: str = "abcc", K = 2 Output: 2 Explanation: Possible substrings of length K = 2 are ab : 2 distinct characters bc : 2 distinct characters cc : 1 distinct character Only two valid subst Aug 20, 2015 · I have to count the number of distinct characters alphabet in the string, so in this case the count will be - 3 (d, k and s). The length of the longest non-repeating character substring is 7. We have discussed different solutions in below post. The following query does that, looking in sys. Solution. Input : aaa. Substrings of Size Three with Distinct Characters - LeetCode Initialize a HashMap that stores the character count for each character in the current window. I am not sure how to calculate the time complexity of Can you solve this real interview question? Longest Substring Without Repeating Characters - Given a string s, find the length of the longest substring without repeating characters. Take frequency array array [26]. For k = 3, o/p is ‘bcbdbdbbdcd’. 5. Naive approach: A simple solution is to consider each substring and check if it contains k distinct Substrings of length k with k-1 distinct elements. Constraints: 1 <= s. The first line of the input is the non-empty string s, consisting of small English letters, the string's length is at most 1500 characters. 2 Keep count of the valid substrings. If then, the answer is , the character of the 1-indexed concatenated string. If you only use the 32-128 ASCII code range, then you can simply see if you have any of the characters 32-128, one by one. It should return the kth character from the concatenated string, 1-based indexing. The first line of input for each test case/query contains an integer K. Explanation: The substring [2, 7] is a valid substring in which every character occurs even number of times, and “ssffbb” is the largest lexicographically string that is possible after rearranging the characters. Output: 56. May 6, 2021 · Count substrings made up of a single distinct character; Find the String having each substring with exactly K distinct characters; Check equal frequency of distinct characters in string with 1 or 0 removals; Count substrings having frequency of a character exceeding that of another character in a string; Check if a substring exists having only May 30, 2021 · Suppose a SET is all distinct character in a string. Explanation: “abab”, “ababcc” and “cc” are substrings having each character exactly 2 times and the maximum Apr 24, 2023 · Longest K unique characters substring. pass 3: (all the strings are of length 4) abcd = 1 strings. There are three substrings aa, cc and cc. Can you solve this real interview question? Number of Substrings Containing All Three Characters - Given a string s consisting only of characters a, b and c. Loop over all substrings with length three of s. Return the number of substrings that satisfy the condition above. They are: “a”, “ab”, “b”, “ba”. In general, for an string of size n, there are n* (n+1)/2 non-empty substrings. ii) For the second test case, either “a” or “b” are the longest substring with at most 1 unique character. You are allowed to change characters at some positions to some other lowercase English letters. Example 1: Input: s = "abcabcbb" Output: 3 Explanation: The answer is "abc", with the length of 3. For example: 'str' = abcad and 'k' = 2. Let’s assume, "s" is s string and we have to find the required minimum number of changes to all substrings to make a distinct string. It is essentially a smaller portion of a string extracted from the original string. The task is to compute the total number of unique substrings of the string inStr. Count substrings with same first and last characters. Input: N = 5, S Apr 8, 2015 · The size of character set is also known. Prerequisite : Print subarrays of a given array. Examples: Input: S = "abcc"Output: 2Explanation:Below are all the possible substrings of S(= "abcc") having the frequency of the You are given a string s s of length n n, consisting of only digits 0 0 to 9 9. Input Format: The first line contains an Integer 'T' which denotes the number of test cases/queries to be run. Substrings of Size Three with Distinct Characters - LeetCode Dec 8, 2023 · The innermost loop prints characters from the currently picked starting point to the picked ending point. Mar 4, 2024 · 💡 Problem Formulation: Given a string, the task is to find all possible substrings of size n that contain exactly k distinct characters. Longest Substring with At Most K Distinct Characters - LeetCode Jan 8, 2024 · the current substring with non-repeating characters with the help of a start and end index. Memory Usage: 14. 1 If the there is no repetition, add that character to substrings. size()-1. The specific characters are given as another string. Longest Substring with At Most K Distinct Characters - Level up your coding skills and quickly land a job. Full-Form: Substring is a portmanteau of “sub” and Substrings of Size Three with Distinct Characters - Level up your coding skills and quickly land a job. While there is a short way to get access to the last n characters of string. 7 => (a1)bc, (a2)bc, bc (a3), (a1) (a2)bc, (a1)bc (a3), (a2)bc (a3), (a1) (a2)bc (a3) I know how to calculate the answer for number of substring with k distinct character Dec 12, 2023 · Output: ssffbb. A simple way is to generate all the substring and check each one whether it has exactly k unique characters or not. 1 MB, less than 73. are 7 substrings : a, abca, b, bcab, c, a and b. In this article, a simple recursive solution is discussed. Map<Character, Integer> visited = new HashMap <>(); String output = "" ; Feb 3, 2023 · Given string str of the lowercase alphabet and an integer K, the task is to count all substrings of length K which have exactly K distinct characters. If the i -th character of this string equals " 1 ", then the i -th English letter is Dec 20, 2021 · Method 1 (Simple : O(n 3)): We can consider all substrings one by one and check for each substring whether it contains all unique characters or not. Substrings of Size Three with Distinct Characters - LeetCode Nov 1, 2023 · Find distinct characters in distinct substrings of a string; Generate a string of size N whose each substring of size M has exactly K distinct characters; Count of substrings of length K with exactly K distinct characters; Check if a K-length substring exists having only 2 distinct characters, each with frequency greater than K/3; Largest index May 9, 2023 · Given a string S consisting of lowercase characters(a-z) only, the task is to print a new string by rearranging the string in such a way that maximizes the number of palindromic substrings. k = 2. com May 22, 2024 · What is a Substring? A substring is a contiguous part of a string, i. Output: 3. Mar 10, 2022 · Count the sum of count of distinct characters present in all Substrings; Count distinct substrings that contain some characters at most k times; Maximize count of occurrences of S2 in S1 as a subsequence by concatenating N1 and N2 times respectively; Count of substrings from given Ternary strings containing characters at least once; Count of We would like to show you a description here but the site won’t allow us. Loop over the characters of the string and count the frequency (how many times it appears in the string) of each distinct character. Input: str = “geeksforgeeks”, K = ‘k’. See full list on tutorialspoint. The subarrays are: In this problem, we are given a string and our job is to count the total number of substrings of the given string that contains exactly k distinct characters. Time Complexity: O (n^2), (The outer loop runs in O (n) time, and the inner loop runs in O (n) in the worst case (considering all unique characters), resulting in a total time complexity of O (n^2). combinations, you can generate all possible starting and ending indices for the substrings in a single line and then loop over these pairs to create the substrings themselves. Substrings of Size Three with Distinct Characters - Level up your coding skills and quickly land a job. It updates max_length whenever a valid substring (with count of unique characters equal to k) that is longer than the current maximum is found. A string inStr is given to us. Check if the characters in the input word are repeated in the generated substrings. 2 SETS are same when they have same characters in them. Return the number of substrings containing at least one occurrence of all these characters a, b and c. Therefore, the answer will be 4. Input: s = “abc”. You have to find the minimum number of changes required to make all the substrings of the string distinct or return -1 if you can't make it. pass 2: (all the strings are of length 3) abc, bcd = 2 strings. For k = 5, o/p is Generate all substrings of the input word, starting from 0 to n. Length of the string − 26 Jun 17, 2022 · You want all substrings of the string 'S' to be distinct. Apr 5, 2023 · For example: 'a' and 'r' are distinct while 'r' and 'r' are same. We fix a starting point, traverse through all substrings starting with the picked point, we keep incrementing frequencies of all characters. Examples: Input: S= ” de”, K = 2. Approach: The idea is to iterate over all the Dec 12, 2022 · The substrings are aa, bb, cc, aabb, bbcc and aabbcc. Approach: The idea is to count occurrences of each character using unordered_map and count the number of removals required for each of them and print the minimum. Sep 11, 2020 · Your task is to find the length of the longest substring that contains at most K distinct characters. Jun 7, 2024 · Given string str of the lowercase alphabet and an integer K, the task is to count all substrings of length K which have exactly K distinct characters. Mar 24, 2023 · Count of all unique substrings with non-repeating characters. For example, Consider the string “geeks”, There are 15 non-empty substrings. Input : s = "aabccc". Jun 25, 2022 · Create an array count [] to store counts of characters. Method 4: Using Collections to Count Uniques Mar 23, 2024 · Given a string S and an integer K, the task is to count the number of substrings which have each character exactly K times and maximum distance between two same characters <= K. For each such substring, check whether the three characters are all distinct. Try It! Method 1 (Brute Force) If the length of string is n, then there can be n* (n+1)/2 possible substrings. Problem Statement Given a string S, the task is to count Count Number of Distinct Substrings in a String in Java. Given a string s , return the number of good substrings of length three in s . Given a String S consisting only lowercase alphabets and an integer K. In other words, find the number of substrings in s that differ from some substring in t by exactly one character. I have done things like this Nov 10, 2023 · Python String: Exercise-76 with Solution. For each of the substring, we only need to compare the 3 characters with 3 comparisons, that is O(1). Output: 5. For k = 2, o/p is ‘bdbdbbd’. You can do it in linear time. We'll explore an efficient algorithm for solving this problem and provide C++ code to implement it. Oct 4, 2023 · Count of Distinct Substrings occurring consecutively in a given String; Count of substrings of a string containing another given string as a substring | Set 2; Count of occurrences of each prefix in a string using modified KMP algorithm; Count of substrings having all distinct characters Explanation for Longest Substring with At Most K Distinct Characters LeetCode Solution: i) For the first test case, “acc” is the longest substring with at most 2 unique characters. Apr 2, 2024 · A more efficient approach is to use a sliding window technique, where we maintain a window of characters in the string and slide it along the string to find all possible substrings that contain exactly k distinct characters. 51% of Python3 online submissions for Substrings of Size Three with Distinct Characters. Output: True. public int countGoodSubstrings(String s) {. Nov 1, 2023 · Given a string S of length N, the task is to check if a string can be split into two non-intersecting strings such that the number of distinct characters are equal in both. Aug 10, 2022 · Minimum length substring with exactly K distinct characters; Convert given string so that it holds only distinct characters; Check if a string can be split into substrings starting with N followed by N characters; Find Kth distinct character from start of given String; Count ways to split a string into two subsets that are reverse of each other Input. Jun 1, 2021 · Suppose we have string s=" aabca " and k= 3. This approach has a time complexity of O(n^2), which is more efficient than the brute force method. , a string inside another string. Whether it’s analyzing textual data or parsing Apr 19, 2023 · Explanation: The given string “geeksforgeeks” contains 7 unique characters {‘g’, ‘e’, ‘k’, ‘s’, ‘f’, ‘o’, ‘r’}. A substring is a contiguous sequence of characters in a string May 31, 2019 · Given string str of the lowercase alphabet and an integer K, the task is to count all substrings of length K which have exactly K distinct characters. In fact I don't know how to use the character size. Example 3: Input: s Apr 23, 2024 · Steps:-. Explanation: Possible substrings of length K = 2 are. Write a Python program to count the number of substrings from a given string of lowercase alphabets with exactly k distinct (given) characters. Examples: Input : abcd. String inStr = "abcde" Output: There are 16 unique substrings. The number of new distinct substrings that end in i is (the length of the prefix) — (maximum value in the z_function array). Whether a substring contains all unique characters or not can be checked in linear time by scanning it from left to right and keeping a map of visited characters. answer=6. To see this, observe that once character b j−1 has been matched, the number of distinct characters seen until b j is matched is 1 if b j matches ¯a I j−1+1,2ifb j matches the first distinct character after that, 3 if it is the second such distinct character, etc. The size of the set after Mar 10, 2024 · The brute force method uses nested loops to generate all possible substrings and a set to calculate the number of unique characters. e. A substring s of word is complete if: * Each character in s occurs exactly k times. Example 1: S = "abcc". Output: cfefd. That is, for any two adjacent characters c1 and c2 in s, the absolute difference in their positions in the alphabet is at most 2. Example 1: Input. a lookup table of already visited characters. Then if a character has a frequency n. The idea is to initialize an unordered set that stores all the distinct characters of the given string. Increment count [x]. It should return the character from the concatenated string, 1-based indexing. For each prefix i of the word, reverse it and do z_function over it. The substrings are a, b, a and aba. (denote it as s) For example, given a string "PccjcjcZ", s = 4, l = 3, then there are 5 distinct substrings: “Pcc”; “ccj”; “cjc”; “jcj”; “jcZ” I try to use hash table, but the speed is still slow. Find the count of all substrings of length K which have exactly K-1 distinct characters. So number of subsequence with 3 distinct characters are -. Input : S = "aba". Naive Approach: The idea is to traverse through all substrings. All Elements are Distinct. Output : aaa aa a aa a a. Then the test cases follow. The source code is as below: May 11, 2024 · Definition: A substring is a contiguous sequence of characters within a larger string. Examples: Input : test_str = ‘geeksforgeeksforgeeks’, N = 3, K = 2. Counting Distinct Substrings In A Given String Using Trie. Note We have distinct substrings here, i. Examples: Input: str = “geeks”, K = ‘g’. To count all substrings in a given string, we do the following : Construct a Trie with all the substrings that are the suffixes of a given string. Jul 10, 2015 · I've got a table with a field that is similar to this: ANIMAL ======== FISH 54 FISH 30 DOG 12 CAT 65 CAT 09 BIRD 10 FISH 31 DOG 10 The field may later have new animals added, such as GOAT 72 DOG Can you solve this real interview question? Substrings of Size Three with Distinct Characters - A string is good if there are no repeated characters. Function Description Complete the ashtonString function in the editor below. Output : [‘gee’, ‘eek’, ‘gee’, ‘eek’, ‘gee’, ‘eek’] Explanation : 3 lengths have 2 unique characters are extracted. Example: Input: abc, k = 2 Output: 2 Possible substrings are {"ab", "bc"} I have written the solution with a two pointer approach. The index of the last character will be the length of the string minus one. Feb 14, 2023 · The task is to find the minimum length substring having exactly K distinct characters. * The difference between two adjacent characters is at most 2. Input : test_str May 15, 2015 · Below is an efficient way to get the unique or distinct values. Given the following String: String input; input = "223d323dk2388s"; c Sep 19, 2023 · Count substrings made up of a single distinct character; Split the string into substrings using delimiter; Count the sum of count of distinct characters present in all Substrings; Find the number of strings formed using distinct characters of a given string; Count the number of vowels occurring in all the substrings of given string Substrings of Size Three with Distinct Characters - Level up your coding skills and quickly land a job. We can see that the substrings {ab, bc, ca, ad} are the only substrings with 2 distinct characters. int n = s. Each of these “next distinct characters” is equally likely to be b . The number of substrings of length 3 is n — 2, that is O(n). Apr 1, 2010 · pass 1: (all the strings are of length 2) ab, bc, cd = 3 strings. foreach i to s. olmrokaveirwobkyyfgv