Print lexicographically smallest string of length n. Return the resulting string.

Print lexicographically smallest string of length n. This is lexicographically smallest strings that Apr 13, 2019 · We traverse remaining substrings, by removing first character of previous substring and adding last character of new string. For ex: In dictionary 'ado' comes after 'adieu' because 'o' comes after 'i' in English alphabetic system. You must make sure your result is the smallest in lexicographical order among all possible results. The goal is to identify the smallest subsequence of length ‘k’ from a given string such that when the characters are compared lexicographically, no other subsequence of the same length is smaller. If the number of possible strings of length N is less than K, print -1. Sep 10, 2025 · Can you solve this real interview question? Using a Robot to Print the Lexicographically Smallest String - You are given a string s and a robot that currently holds an empty string t. For example, given the equivalency information from s1 = "abc" and s2 = "cde", "acd" and "aab" are equivalent strings of baseStr = "eed", and "aab" is the lexicographically smallest equivalent string of baseStr. Examples: Input: s = "bbcaab", k = 3 Output: "aab" Input: s = "aabdaabc", k = 3 Output: "aaa" [Naive Approach] Generating all Subsequences - O (2^n) time and O (C (n,k)*k+n) space The idea is to generate all possible subsequences of length k from the input Another example: if strArr is [aabdccdbcacdaad], then the smallest substring of N that contains all of the characters in K is "aabd" which is located at the beginning of the string. The numeric value of a lowercase alphabetic character is its position in the alphabet starting from 1; hence ‘a’ is 1, ‘b’ is 2, etc. Jul 30, 2022 · Perform second operation four times p="addb", s="", t="". Return the kth string of this list or return an empty string if there are less than k happy strings of length n. length <= 10 5 s consists of only English lowercase letters. Construct Smallest Number From DI String in Python, Java, C++ and more. Example s ="26547". Can you solve this real interview question? Smallest K-Length Subsequence With Occurrences of a Letter - You are given a string s, an integer k, a letter letter, and an integer repetition. * Remove the last A string a is lexicographically smaller than a string b (of the same length) if in the first position where a and b differ, string a has a letter that appears earlier in the alphabet than the corresponding letter in b. Jul 23, 2025 · The lexicographically smallest string is "abcde". For instance, given the input n = 5 and k = 73, the desired Mar 20, 2023 · Given a string S of length N consisting of lowercase English letters and an integer K. For example, “abc” is lexicographically Your task is to find the lexicographically-smallest string L consisting of unique characters of lower case Latin letters (a-z) and which follows the relations mentioned in S. nsmallest () method takes O (k log n) time, where k is the number of smallest elements to be retrieved and n is the length of the input list. If more than one string occurs maximum number of times, then print the lexicographically smallest substring. Time Complexity: O (N!), where N is the length of the given string. Approach: For K?N, the lexicographically smallest possible string will be 'a' repeated N times, since, in N operations, all the characters of S can be changed to 'a'. We can do this modifications any number of times, find the lexicographically smallest string possible. charAt (pos) - 'a']--; while (t. Input: S Can you solve this real interview question? Lexicographically Smallest String After Operations With Constraint - You are given a string s and an integer k. You are given a string of length n n. Jul 23, 2025 · A substring is a contiguous part of a string, i. This operation can be performed at most one time. Apply one of the following operations until s and t are both empty: * Remove the first character of a string s and give it to the robot. Here, ‘distance’ means the total difference in alphabetical positions of adjacent characters. The third string is "c". deleteCharAt (t. A … Jul 23, 2025 · Given a binary string s of length N, the task is to find the lexicographically smallest string using infinite number of swaps between 0's and 1's. Mar 2, 2024 · Problem Formulation: You need to find the smallest lexicographic string of lowercase letters with a specified length k and a non-repeating character distance of n. Jul 23, 2025 · Given two strings X and Y of lowercase letters, of length N and M respectively, the task is to build another string Z by performing two types of operations: Choose any character from the string X, remove it from X, and add it to the end of Z. Apr 27, 2023 · The task is to print the K-th lexicographically the smallest one among the different substrings of s. Method 1 Find the lexicographically smallest string t of length k, such that its set of letters is a subset of the set of letters of s and s is lexicographically smaller than t. Sample Input 0 welcometojava 3 Sample Output 0 ava wel Explanation 0 String has the following lexicographically-ordered substrings of length : We then return the first (lexicographically smallest) substring and the last (lexicographically largest) substring as two newline-separated values (i. At the end, add 1 with rank and return it as the required answer. If all of its distinct substrings are ordered lexicographically, what is the k k th smallest of them? Input The first input line has a string of length n n that consists of characters a–z. On, the basis of this definitions, let’s suppose a string s, and an integer k are passed as input. Jul 23, 2025 · Lexicographically smallest palindrome with minimal changes Strings of length N with no palindromic sub string Check if any anagram of a string is palindrome or not Count maximum-length palindromes Next greater palindromic number Hard Problems: Minimum insertions to form a palindrome Longest Palindromic Substring Checking palindrome in a stream Construct Smallest Number From DI String - You are given a 0-indexed string pattern of length n consisting of the characters 'I' meaning increasing and 'D' meaning decreasing. , if the length of the string is a power of 2, reduce k by half, else multiply k by 2. 3K subscribers Subscribe Mar 4, 2024 · Problem Formulation: Given a string, the challenge is to find the lexicographically smallest string possible after applying a series of operations. That is, two indices 1 <= i, j <= n can be chosen and swapped. Example 1: Input: abczd Output: abcd Example 2: Input: abcda Output: abca Explanation: One can remove d to get abca, which is the lexicographically smallest string possible Jul 23, 2025 · Given a string S consisting of digits from 0 to 9 inclusive, the task is to form the lexicographically smallest string by performing an operation any number of times. Apply one of the following operations until s and t are both empty: Remove the first character of a string s and give it to the robot. 2434. * Remove the last Sep 14, 2022 · Given a number K and a string S, We have to Find the lexicographically smallest string str of length K such that it's set of letters is a subset of the set of letters of S and S is lexicographically smaller than str. * Remove the last Aug 30, 2017 · 11 Lexicographical ordering means dictionary order. For instance, if k=3 and n=6, a valid string could be “abf” (since 1+5=6), with the desired output being “abf”. min (s [i] + 1, 9) and place it in any position of the string. The robot will append this character to the string t. There´s a part in this solution I don´t really understand. There is a string $s$ of length $n$ containing lowercase letters and an integer $k$. Add that value to the rank. Output Print the only string a — the lexicographically smallest string concatenation. We will create a function so that it finds the lexicographically smallest and largest substrings of length. Result = "24677 To find the smallest of given List of strings lexicographically in Python, call min () builtin function and pass the list of strings as argument. Examples: Input : str[] = "abc", n = 3 Output : Result = "bac" Explanation : All possible permutation in sorted order: abc, acb, bac, bca, cab, cba Input : str[] = "aba", n = 2 Output : Result = "aba" Explanation : All possible permutation in sorted order: aab, aba In-depth solution and explanation for LeetCode 2734. Jul 23, 2025 · Given a string S of N characters, the task is to find the smallest lexicographical string after performing each of the following operations N times in any order: Apr 8, 2020 · Its a program to print the Lexicographically smallest and largest substring of size k. Calculate the number of lexicographically smaller that can be formed using them as shown above. Your task is to apply these operations until both s and t are empty, and determine the lexicographically smallest string that can be obtained as the result. Both parameters will be strings ranging in length from 1 to 50 characters and all of K's characters will exist somewhere in the string N. The second input line has an integer k k. I found out that for that you have to use the compareTo() method, the problem is that when I try to do if 2434. Apr 12, 2023 · Creating a list of all string elements using list comprehension takes O (n) time, where n is the length of the input list. Mar 9, 2024 · Problem Formulation: In the context of string processing, finding the lexicographically smallest subsequence of a given size can be a common task. Can you solve this real interview question? Smallest Subsequence of Distinct Characters - Given a string s, return the lexicographically smallest subsequence of s that contains all the distinct characters of s exactly once. Jul 15, 2020 · Naive Approach: The simplest idea is to generate all possible permutation of the given string and check whether which lexicographically smallest string satisfies the conditions for at most K swaps. A string x is lexicographically smaller than a string y of the same length if x[i] comes before y[i] in alphabetic order for the first position i such that x[i] != y[i]. May 4, 2025 · Given a string s consisting of only lowercase characters, the task is to find the lexicographically smallest string after removing exactly k characters from the string. Note that a string x is lexicographically smaller than string y if x comes before y in dictionary order, that is, either x is a prefix of y, or if i is the first position such that x [i] != y [i], then x [i] comes before y [i] in alphabetic order. Can you solve this real interview question? Lexicographically Smallest Generated String - You are given two strings, str1 and str2, of lengths n and m, respectively. The task is to print the lexicographically smallest string of length N consisting of lower-case English alphabets such that the sum of the characters of the string equals K where 'a' = 1, 'b' = 2, 'c' = 3, . Using a Robot to Print the Lexicographically Smallest String 2434. Here’s an example: Jul 23, 2025 · Modified string = "aaaa". The heapq. Perform the following operation: * Select any non-empty substring then replace every letter of the substring with the preceding letter of the English alphabet. LeetCode Solutions in C++, Java, and Python. Example 1: Input: n = 1, k = 3 Output: "c" Explanation: The list ["a", "b", "c"] contains all happy strings of length 1. You have to find the n-th permutation of string lexicographically. In one operation you can choose any position i and delete the digit d at s [i] and insert min (d+1, 9) on any position (at the beginning, at the end, or in between any two adjacent digits). A 0-indexed string num of length n + 1 is created using the following conditions: * num consists of the digits '1' to '9', where each digit is used at most once. Examples Input 4 abba abacaba bcd er Output abacabaabbabcder Input 5 x xx xxa xxaa xxaaa Output xxaaaxxaaxxaxxx Input 3 c cb cba Output cbacbc Topic Link Can you solve this real interview question? Lexicographically Smallest String After Operations With Constraint - You are given a string s and an integer k. Examples: Input: S = "aabacdefghijklmnopqrstuvwxyz" Output: ad Explanation: All the single digit strings from [a-z] occur in the given string and in two character strings, strings {aa, ab, ac} occur but "ad" is not present in the given string. Key Insights Start with a string filled with the smallest character 'a', which gives the minimum possible sum of n. So, we just need to print the lexicographically smallest character present in the string. append (t. Jul 12, 2025 · Given a string str of length N. length () - 1) <= smallest (rightFreq)) { res. Jul 15, 2025 · Given a string str, the task is to find the substring of length K which occurs the maximum number of times. , a string inside another string. Jul 23, 2025 · Explanation: Lexicographically smallest subsequence possible is "xvsjas". Dec 29, 2022 · Time Complexity: O (N^2), where N is the length of the string. Your task is to determine the lexicographically minimal rotation of a string. You are allowed to replace at most one character in the string with an arbitrary lowercase Latin letter. Instead check if appending b at the end of a produces a lexicographically smaller string or appending a at the end of b does. Examples: Input: s = "1001001" Output: 0000111 Explanation: Lexicographically smallest string of 1001001 is only 0000111 Input: s = "0001" Output: 0001 Microsoft Online Assessment (OA) - Lexicographically Smallest String Given a string str, the task is to find the lexicographically smallest string that can be formed by removing at most one character from the given string. Output Print the k k th smallest distinct substring in lexicographical order. charAt (t. Examples: Input: s = “04829” Output Feb 12, 2025 · -3 I have a string of size n, containing only numbers from 0 to 9 pick any character from this string and modified it using formula Math. Note: The set of letters is a set, not a multiset. Mar 2, 2024 · For finding the lexicographically smallest string, we perform a depth-first search on the graph of possible moves, backtracking as soon as a move does not lead us closer to the destination or if we’ve found a string that is not the smallest in lexicographical order. These operations could include character replacements, rotations, or any other manipulations that affect the string ordering. Dec 22, 2022 · Given two integers N and K. You can remove any k character. Mar 4, 2024 · Problem Formulation: We need to create a program that, given two integers n and k, returns the lexicographically smallest string that has a length equal to n and a numeric value equal to k. Jul 23, 2025 · Given a string s, the task is to find the lexicographically smallest string of minimum characters that do not exist as a substring in S. Define a function distance(s1, s2) between two strings s1 and s2 of the same length n as: * The sum of the minimum distance between s1[i] and s2[i] when the characters from 'a' to 'z' are placed in a cyclic order, for all i in the range [0 May 8, 2023 · Given String str and an integer k, find the lexicographically smallest and largest substring of length k Lexicography order, also called as alphabetical order or dictionary order, Return the lexicographically smallest string you can obtain by applying the above operations any number of times on s. Examples: Input: str = "ccad Oct 13, 2014 · When comparing strings with operator &lt;, what is the smallest string? To be more specific, what is a string that is smaller (using &lt;) than any other string? Print the single line containing the lexicographically smallest string, that can be obtained using the procedure described above. The test cases are generated so that the letter appears in s at least Jul 23, 2025 · Given an array arr [] consisting of N strings and a string S if size M, the task is to find the lexicographically smallest string consisting of the string S as the prefix. Examples: Input: str = "string" Output: gtrins Explanation: Choose i=1, j=6, string becomes - gtrins. Dec 30, 2015 · The smallest lexicographical order is an order relation where string s is smaller than t, given the first character of s (s1) is smaller than the first character of t (t1), or in case they are equivalent, the second character, etc. May 3, 2023 · Given a string of length m containing lowercase alphabets only. , dictionary order). Now delete any (k-1) occurrences of this letter from the string in a way so that the resultant string is lexicographically smallest. Return the lexicographically smallest subsequence of s of length k that has the letter letter appear at least repetition times. Remove the first character from s and append it to t. You can make minimal changes to the characters in the string and you can permute the string. For the substring check part, Sep 18, 2023 · Return the lexicographically smallest string you can obtain after performing the above operation exactly once. Maybe someone can explain it to me. In general, for an string of size n, there are n* (n+1)/2 non-empty substrings. Now, sort the array and print the string at 0th position for the smallest lexicographically subsequence. A substring of s is a string obtained by taking out a non-empty contiguous part in s. Jul 12, 2025 · Given string str of lower case English alphabets. length () - 1); } pos++; } return res. Solutions Solution 1: Greedy + Stack The problem can be transformed into, given a string sequence, convert it into the lexicographically smallest string sequence with the help of an auxiliary stack. The function returns the string that occurs first when sorted lexicographically in ascending order. Jul 15, 2025 · Given two integers N and K, the task is to find lexicographically Kth string of length N. The Format of Input: Jun 6, 2025 · rightFreq [s. The task is to find the lexicographically smallest string possible by inserting a given character. Find the lexicographically smallest string T of length K, such that its set of letters is a subset of the set of letters of S and T is lexicographically greater than S. Auxiliary Space: O (N^2) Efficient Approach: An observation here is that a single character is also a palindrome. Auxiliary Space: O (1) Aug 26, 2022 · The task is to find the lexicographically smallest string X of the same length only that can be formed using the operation given below: In a single operation, select any one character among the at most first K characters of string S, remove it from string S and append it to string X. Remove the last character from t and append it to a result string (written on paper). , ava\nwel). A string a is lexicographically smaller than a string b (of the same length) if in the first position where a and b differ, string a has a letter that appears earlier in the alphabet than the corresponding letter in b. Aug 28, 2020 · Here's the problem statement Given a sequence of n integers arr, determine the lexicographically smallest sequence which may be obtained from it after performing at most k element swaps, each invol Can you solve this real interview question? Break a Palindrome - Given a palindromic string of lowercase English letters palindrome, replace exactly one character with any lowercase English letter so that the resulting string is not a palindrome and that it is the lexicographically smallest one possible. We keep track of the lexicographically largest and smallest. Using a Robot to Print the Lexicographically Smallest String Table of contents Description Solutions Solution 1: Greedy + Stack For each test case, print the answer on it: the lexicographically minimum possible string of length n you can obtain from the given one if you can perform no more than k moves. e. Naive Approach: The simplest approach is to generate all possible subsequences of length (N - 1) from the given string and store all subsequences in an array. Using a Robot to Print the Lexicographically Smallest String Problem You are given a string s and a robot that currently holds an empty string t. One can choose any two characters in the string and replace all the occurrences of the first character with the second character and replace all the occurrences of the second character with the first character. Return the resulting string. toString (); } } #Python class Solution: def smallest (self, right_freq): for i in range (26): if right_freq [i] > 0: return chr (97 In-depth solution and explanation for LeetCode 2375. Lexicographically smallest string | Problem of the Day : 06/10/22 | Siddharth Hazra GeeksforGeeks Practice 84. Jun 6, 2025 · We need to find the lexicographically smallest string that can be written on the paper by a robot using two operations: moving the first character of the string s to the robot's string t (stack), or moving the last character of t to the paper. Below is the implementation of the above approach: Find the solution of Using a Robot to Print the Lexicographically Smallest String Leetcode question with step by step explanation in 2 approaches and 3 solutions in languages like Java, CPP, Python. Apply this operation as many times as he wants. Print the lexicographically minimal string that can be obtained from the original string and contains the maximum number of palindromes as substrings. Remove the For each test case, print the answer on it: the lexicographically minimum possible string of length n n you can obtain from the given one if you can perform no more than k k moves. Examples: Input: s = "acab" Output: abac Explanation: All possible rotations are: "acab", "caba", "abac" and "baca". Apr 13, 2021 · The row with lexicographically shortest firstName : If there are more than one strings of the same minimum length, and we want to retrieve, lexicographically, the shortest string then can do as following: Feb 18, 2025 · LeetCode 2375: Construct Smallest Number From DI String You are given a 0-indexed string pattern of length n consisting of the characters 'I' meaning increasing and 'D' meaning decreasing. Dec 7, 2023 · Given a circular string s, find whether there exists a permutation of s which is a K-periodic circular string and if it exists then find the lexicographically smallest permutation of s which is a K-periodic circular string. Feb 1, 2023 · The correct approach is to use a regular sorting algorithm. Constraints: 1 <= s. The lexicographically smallest Remove Duplicate Letters - Given a string s, remove duplicate letters so that every letter appears once and only once. If there is no way to replace a character to make it not a You are given a string s s of length n n, consisting of lowercase Latin letters. When two strings a and b are compared to decide if they have to be swapped or not, do not check if a is lexicographically smaller than b or not. . I have to create a program that takes 3 strings and orders them in a lexicographic order. Mar 19, 2023 · Given a string S. * Remove the last Jul 23, 2025 · A rotation of a string can be generated by moving characters one after another from beginning to end. Approach: The idea is to place the character just before the first character which is lexicographically greater than the character C in the string. May 6, 2025 · Given a string s of length n, the task is to find the lexicographically smallest k-length subsequence from the string s (where k < n). [the reason is mentioned above] Below is the implementation of the above approach. Aug 13, 2025 · This blog will discuss the problem to find the lexicographically smallest K-length subsequence from a given string in C++, Java, and Python language along with the time and space complexity. Jun 28, 2020 · How to find the lexicographically smallest and largest substring? Write a program to sort the sub-strings in lexicographical order in Java and Python. Can you solve this real interview question? Lexicographically Smallest String After Substring Operation - Given a string s consisting of lowercase English letters. and 'z' = 26. Sep 27, 2025 · Can you solve this real interview question? Using a Robot to Print the Lexicographically Smallest String - You are given a string s and a robot that currently holds an empty string t. A substring is a contiguous sequence of characters in a string. Jul 23, 2025 · Iterate the string from i = 0 to length of string: Find the number of characters smaller than the current character. Return the resulting palindrome string. But you have to modify the value of k, i. Input: S = "geeksforgeeks", K = 6 Output: aaaaaaeegeeks Explanation: After 6 operations, lexicographically smallest string will be "aaaaaaeegeeks". Find the lexicographically smallest string that can be obtained by doing this operation at most once. The k-th Lexicographical String of All Happy Strings of Length n in Python, Java, C++ and more. The sum of string lengths will not exceed 5·104. public static Lexicographically Smallest Generated String - You are given two strings, str1 and str2, of lengths n and m, respectively. Jul 23, 2025 · Given three strings, S1, S2, and S3. Can you solve this real interview question? Using a Robot to Print the Lexicographically Smallest String - You are given a string s and a robot that currently holds an empty string t. Mar 9, 2024 · Problem Formulation: The challenge involves writing a program in Python to determine the kth smallest string of length n, ordering strings in lexicographical order (i. For example, 'b' is converted to 'a', and 'a' is converted to 'z Oct 23, 2021 · Problem Statement Given a string S. For example, the rotations of acab are acab, caba, abac, and baca. Among the letters those appear exactly $k$ times in string $s$, pick the lexicographically maximum one. Jul 23, 2025 · Given a string S consisting of lowercase alphabets, the task is to find the lexicographically smallest string that can be obtained by removing duplicates from the given stringS. Calculate the remaining value to be distributed by subtracting n from k. Return an empty string if there does not exist a valid permutation of s which is a K-periodic circular string. Return the lexicographically smallest equivalent string of baseStr by using the equivalency information from s1 and s2. Lexicographically Smallest String After Substring Operation in Python, Java, C++ and more. Mar 30, 2020 · First to get the lexicographically smallest values between a list of strings and then to check if it is not a substring in the given strings. Define a function distance(s1, s2) between two strings s1 and s2 of the same length n as: * The sum of the minimum distance between s1[i] and s2[i] when the characters from 'a' to 'z' are placed in a cyclic order, for all i in the range [0 Leetcode 1415: The k-th smallest string in lexicographical order among happy strings of length n (super detailed solution!!!), Programmer Sought, the best programmer technical posts sharing site. This ordering is not based on length of the string, but on the occurrence of the smallest letter first. length () - 1)); t. Print the lexicographically smallest string possible. length () > 0 && t. A string word of length n + m - 1 is defined to be generated by str1 and str2 if it satisfies the following conditions for each index 0 <= i <= n - 1: * If str1[i] == 'T', the substring of word with size m starting at index i is In-depth solution and explanation for LeetCode 1415. The characters at the same index in S1 and S2 are considered equivalent and follow the transitive property, the task is to find and print the lexicographically smallest string that you can obtain from S3 by changing its characters to some other equivalent character obtained from S1 and S2. 6 days ago · Can you solve this real interview question? Using a Robot to Print the Lexicographically Smallest String - You are given a string s and a robot that currently holds an empty string t. The task is to find out the lexicographically smallest string when at most only one swap is allowed. Print that string. Intuitions, example walk through, and complexity analysis. A string a is lexicographically smaller than string b (of the same length) if in the first position where a and b differ, string a has a letter that appears earlier in the alphabet than the corresponding letter in b. Modify the string from the end (rightmost position) to maintain lexicographical order, replacing 'a' with higher characters as needed. Better than official and forum solutions. What's the best algorithm to find all binary strings of length n that contain k bits set? For example, if n=4 and k=3, there are 0111 1011 1101 1110 I need a good way to generate these given a Nov 18, 2016 · For example, suppose that you wanted to know the first letter of the $n$th lexicographically smallest non-empty string of length at most $k$ over the alphabet $S$. 5dv6 ff3 e0n 9tri dc9 ix sckfp j3gb bkhk daabk