Find all possible combinations of string in java. For example, given the following lists: X: [A, B, C] Y: [W.
Find all possible combinations of string in java We will examine many approaches to producing every possible combination of a given string in this section. Examples: Input : 123 Output :1 2 3 1 23 12 3 Jun 15, 2016 · Consider the combination as a binary sequence, if all the 4 are present, we get 1111 , if the first alphabet is missing then we get 0111, and so on. In the context of computer science and programming, “ string combinations ” refer to the various ways in which you can arrange or select characters from a given string. Below is the code for the above approach: Feb 14, 2025 · The idea is to recursively generate all possible substrings of the given string s. and so on. There are a few ways to do this with Java, including repetition, and recursion. The first case is the element included in the current combination. Method 1: Using Recursion AllCombinations. Nov 23, 2021 · Approach: Count the occurrences of all the characters in the string using a map, then using recursion all the possible combinations can be printed. May 20, 2025 · Your task is to generate and print all possible combinations of exactly r elements from this array. Note: A combination is a selection of items where the order does not matter. a slight performance improvement i'd do is pass a StringBuilder instead of a String - a String in java is immutable so every time you call curr += alphabet[i] youre actually allocating a new String object. Aug 13, 2024 · Given an input string of numbers, find all combinations of numbers that can be formed using digits in the same order. One of the most popular programming problems is to create every conceivable string combination. To do so, create an array of string res [] to store the substrings of string s and an empty string cur to store the current string. And then in the final string , you should replace all the occurrence of '~' with guessedPw, and get the answer string. In this method, we consider the elements of the given array and recure using the two cases. Jul 23, 2025 · Time complexity: O (n * 2^n * n!) Auxiliary Space : O (2^n * n) Approach 2 : Generate all possible combinations of the given string using a bitmask. Once stored, generate all possible permutations of 2 characters and store them. In Java, this can be achieved using recursive methods or iterative approaches. Generating all possible combinations of letters from a string involves creating permutations of the characters in the string. Two combinations that differ only in ordering of their characters are the same combination. Once the last step is completed, discard all permutations of a single character. + Ncn = 2 Pow N So you get 2 Pow N combinations for given word of length N characters. java Output: abc ab In this post, you will learn how to write a program to find all possible combinations of String in Java. All combination of string in java is the companion problem to find permutation of the string . Jun 19, 2013 · Given an unknown amount of lists, each with an unknown length, I need to generate a singular list with all possible unique combinations. Jun 16, 2013 · 2) the number of elements per result set not being fixed: a combination possibility is per example merging all lists into one. Store the elements and their counts in two different arrays. Feb 2, 2024 · Use Include-Exclude to Generate All Possible Combinations in Java Similarly, we create an empty array and use the Pascal identity problem to generate all the possible combinations of an array. For each combination, generate all possible permutations of the characters in that combination. Print each permutation. What is an elegant way to find all the permutations of a string. The combination generated from the algorithm has range in length from one to the length of the string. A permutation is an arrangement of all or part of a set of objects, with regard to the order of the arrangement. All combinations of a String In Java To find the combinations of a string, either the logic needs to use for loop or recursive loop. So for n alphabets we'll have 2^n -1 (since 0 is not included) combinations. A combination is a selection of items from a larger set, where the order of the selected items doesn’t matter. instead you could append the character to a StringBuilder (and delete the last character when you leave) to save on the number of Objects created during the run for(int Dec 8, 2022 · Given a string str, the task is to print all the permutations of str. g. or each element in a list of its own or merging two elements in a list and the rest in another. Jul 23, 2025 · Follow the below steps to solve the problem: Generate all possible permutations that can be created with 1 character, which is the given array arr []. E. The second case is that element is excluded Jan 23, 2012 · 40 Simplest way of calculating the possible combinations of strings is here Mathematically to find R combinations in a given lot of N = NcR So what we are finding here is, all possible combinations = Nc0 + Nc1 . permutation for ba, would be ba and ab, but what about longer string such as abcdefgh? Is there any Java implementation example? Feb 12, 2014 · your code looks fine. For example, given the following lists: X: [A, B, C] Y: [W So using the idea of power sets, and ordered permutations of the guava library, im able to obtain an array of all the combinations of elements inside my original array. As for loop depends on the string length, for each loop we have to write the logic again, as more swapping will happen when try to get the combinations. Dec 2, 2016 · Now first you need to look for all possible combinations of str, finding which will take exponential time , and then for each found combination, you should generate all it's permutation , which is again factorial time complex. Store all permutations. . ptgpaexhdzjanohjahqthoicbgcpolrjemzoomizopxnrymywwljdqdnfhyrctikxafyrri