Given an array of size n, generate and print all possible combinations of r elements in array. We first fix 1 at index 0 in data[], then recur for remaining indexes, then we fix 2 at index 0 and recur. Finally, we fix 3 and recur for remaining indexes.

When number of elements in data[] becomes equal to r size of a combinationwe print data[]. Following diagram shows recursion tree for same input.

Following is implementation of above approach. How to handle duplicates? We can avoid duplicates by adding following two additional things to above code. See this for an implementation that handles duplicates. Method 2 Include and Exclude every element Like the above method, We create a temporary array data[].

The idea here is similar to Subset Sum Problem. We one by one consider every element of input array, and recur for two cases:. Following is implementation of method 2. How to handle duplicates in method 2? Like method 1, we can following two things to handle duplicates.

## C++ Program to Generate All Possible Combinations of a Given List of Numbers

Below is another DFS based approach to solve this problem. Make all combinations of size k. This article is contributed by Bateesh. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

Attention reader! Writing code in comment? Please use ide. This function. Ending indexes in arr[]. This function mainly uses combinationUtil. The condition. Program to print all combination. The main function that prints. A temporary array to.

Print all combination. Current combination is ready. This code is contributed by mits. WriteLine "". This function mainly.

The main function that prints all. This function mainly uses.GitHub is home to over 50 million developers working together to host and review code, manage projects, and build software together. Work fast with our official CLI. Learn more. If nothing happens, download GitHub Desktop and try again. If nothing happens, download Xcode and try again.

### Print all possible strings of length k that can be formed from a set of n characters

If nothing happens, download the GitHub extension for Visual Studio and try again. We use optional third-party analytics cookies to understand how you use GitHub.

You can always update your selection by clicking Cookie Preferences at the bottom of the page. For more information, see our Privacy Statement. We use essential cookies to perform essential website functions, e. We use analytics cookies to understand how you use our websites so we can make them better, e.

Skip to content. Dismiss Join GitHub today GitHub is home to over 50 million developers working together to host and review code, manage projects, and build software together.

Sign up. Go back. Launching Xcode If nothing happens, download Xcode and try again. Latest commit. Get Path - BFS. Git stats commits.

Failed to load latest commit information. AllWays DP. BFS Graph. DeleteLL Rec. EditDist DP.Below is a picture of such keypad. Given a keypad as shown in the diagram, and an n digit number, list all words which are possible by pressing these numbers.

Approach: It can be observed that each digit can represent 3 to 4 different alphabets apart from 0 and 1. So the idea is to form a recursive function. Then map the number with its string of probable alphabets, i. Now the recursive function will try all the alphabets, mapped to the current digit in alphabetic order and again call the recursive function for the next digit and will pass on the current output string.

## Mobile Numeric Keypad Problem

Implementation: Note that input number is represented as an array to simplify the code. This article is contributed by Jitendra Sangar. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above. Attention reader! Writing code in comment? Please use ide. Example: Input number: Output: adg adh adi aeg aeh aei afg afh afi bdg bdh bdi beg beh bei bfg bfh bfi cdg cdh cdi ceg ceh cei cfg cfh cfi Explanation: All possible words which can be formed are Alphabetical order : adg adh adi aeg aeh aei afg afh afi bdg bdh bdi beg beh bei bfg bfh bfi cdg cdh cdi ceg ceh cei cfg cfh cfi If 2 is pressed then the alphabet can be a, b, c, Similarly, for 3, it can be d, e, f, and for 4 can be g, h, i.

Input number: 5 Output: j k l Explanation: All possible words which can be formed are Alphabetical order : j, k, l, only these three alphabets can be written with j, k, l. The output words are one by one stored. It creates an output array and. A recursive function to print all. Try all 3 possible characters. A wrapper over printWordsUtil. This code is contributed by prajmsidc. Load Comments. We use cookies to ensure you have the best browsing experience on our website.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I just tried for my first programming interview and one of the questions was to write a program that given a 7 digit telephone number, could print all possible combinations of letters that each number could represent.

A second part of the question was like what about if this would have been a 12 digit international number? How would that effect your design. I don't have the code that I wrote in the interview, but I got the impression he wasn't happy with it. What is the best way to do this? Then, for each character in the input string, it looks up the list of letters that match it from the dict defined at the top. It then replaces the list ret with the every combination of existing prefix and possible letter.

It is similar to a question called letter combinations of a phone numberhere is my solution. It works for an arbitrary number of digits, so long as the result doesn't exceed the memory limit. The obvious solution is a function to map a digit to a list of keys, and then a function that would generate the possible combinations:. One way to do it is to look at each possibility for digit matching as a digit in a number on base 4 and implement something close to a counter jumping over some instances, since there are usually less than 4 letters mappable to a digit.

The more obvious solutions would be nested loops or recursion, which are both less elegant, but in my opinion valid. Another thing for which care must be taken is to avoid scalability issues e. Anyone, who requires more illustration to understand the logic, can combine recursion technique with following output:. In numeric keyboards, texts and numbers are placed on the same key.

Given a keypad as shown in diagram, and a n digit number, list all words which are possible by pressing these numbers. For example if input number ispossible words which can be formed are Alphabetical order : adg adh adi aeg aeh aei afg afh afi bdg bdh bdi beg beh bei bfg bfh bfi cdg cdh cdi ceg ceh cei cfg cfh cfi.

How many words are possible with seven digits with each digit representing n letters? For first digit we have at most four choices, and for each choice for first letter, we have at most four choices for second digit and so on. For number above Do you see any pattern? Yes, we notice that the last character always either G,H or I and whenever it resets its value from I to G, the digit at the left of it gets changed. Similarly whenever the second last alphabet resets its value, the third last alphabet gets changes and so on.

First character resets only once when we have generated all words. This can be looked from other end also. We go till the end and come back one by one. Perfect condition for recursion. When we reach at the last character, we print the word with all possible characters for last digit and return. Simple base case.

Following is C implementation of recursive approach to print all possible word corresponding to a n digit input number. Note that input number is represented as an array to simplify the code. In JavaScript. A CustomCounter class takes care of incrementing indexes.Given a number, print all possible combinations of strings that can be used to dial the given number in a phone with following specifications.

The idea is to store digit to characters mapping in hash map. The map stores all characters that can be used dial a digit. We place every possible character for current digit and recur for remaining digits. Below is Java implementation of this idea. This article is contributed by Phalgun. If you like GeeksforGeeks and would like to contribute, you can also write an article and mail your article to contribute geeksforgeeks.

See your article appearing on the GeeksforGeeks main page and help other Geeks. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

Attention reader! Writing code in comment? Please use ide. StringBuilder str. Print all strings of maximum length from an array of strings Print all possible strings that can be made by placing spaces All possible strings of any length that can be formed from a given string Print all possible strings that can be made by placing spaces Check if all strings of an array can be made same by interchanging characters Number of common base strings for two strings Check whether an array of strings can correspond to a particular number X Maximum number of strings that can be formed with given zeros and ones Check if a string can be split into two strings with same number of K-frequent characters Pairs of complete strings in two sets of strings Search in an array of strings where non-empty strings are sorted Count of strings that become equal to one of the two strings after one removal.

Load Comments. We use cookies to ensure you have the best browsing experience on our website.Given the mobile numeric keypad. You can only press buttons that are up, left, right or down to the current button.

You are not allowed to press bottom row corner buttons i. Given a number N, find out the number of possible numbers of given length. If we start with 0, valid numbers will be 00, 08 count: 2 If we start with 1, valid numbers will be 11, 12, 14 count: 3 If we start with 2, valid numbers will be 22, 21, 23,25 count: 4 If we start with 3, valid numbers will be 33, 32, 36 count: 3 If we start with 4, valid numbers will be 44,41,45,47 count: 4 If we start with 5, valid numbers will be 55,54,52,56,58 count: 5 ……………………………… ……………………………….

Keep doing this until N length number is obtained depth first traversal. Recursive Solution: Mobile Keypad is a rectangular grid of 4X3 4 rows and 3 columns Lets say Count i, j, N represents the count of N length numbers starting from position i, j. Following is the implementation of above recursive formula.

Dynamic Programming There are many repeated traversal on smaller paths traversal for smaller N to find all possible longer paths traversal for bigger N. See following two diagrams for example. Since the problem has both properties: Optimal Substructure and Overlapping Subproblemsit can be efficiently solved using dynamic programming. Following is the program for dynamic programming implementation. A Space Optimized Solution: The above dynamic programming approach also runs in O n time and requires O n auxiliary space, as only one for loop runs n times, other for loops runs for constant time.

We can see that nth iteration needs data from n-1 th iteration only, so we need not keep the data from older iterations.

We can have a space efficient dynamic programming approach with just two arrays of size Thanks to Nik for suggesting this solution. This article is contributed by Anurag Singh. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

Attention reader! Writing code in comment? Please use ide. If we start with 0, valid numbers will be 00, 08 count: 2 If we start with 1, valid numbers will be 11, 12, 14 count: 3 If we start with 2, valid numbers will be 22, 21, 23,25 count: 4 If we start with 3, valid numbers will be 33, 32, 36 count: 3 If we start with 4, valid numbers will be 44,41,45,47 count: 4 If we start with 5, valid numbers will be 55,54,52,56,58 count: 5 ……………………………… ……………………………… We need to print the count of possible numbers.

Length j. Lengths 0 and 1. Length k keypad[i,j]. Length k-1 from that new digit and. Add in count we found so far. Length "n". Write "Count for numbers of. But it can always be written as DFS on 4X3 grid.

But it can always be. A Space Optimized Python program to count. Return count of all possible numbers. Here we are explicitly writing lines for each number 0. Get count of all possible numbers of length "n" starting. Driver program to test above function. This code is contributed by.Given a set of characters and a positive integer k, print all possible strings of length k that can be formed from the given set. The idea is to start from an empty output string we call it prefix in following code.

**Arduino Matrix Keypad Tutorial (#19 Ultimate Beginner's Guide to Arduino)**

One by one add all characters to prefix. For every character added, print all possible strings with current prefix by recursively calling for k equals to k The above solution is mainly generalization of this post. This article is contriibuted by Abhinav Ramana. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

Attention reader!

Get hold of all the important Java and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready. Writing code in comment? Please use ide. String prefix. Python 3 program to print all. The method that prints all. It is mainly a wrapper over. The main recursive method. Base case: k is 0. One by one add all characters. Next character of input added. This code is contributed.

WriteLine prefix. WriteLine "First Test".

### All combinations of strings that can be used to dial a number

Recommended Posts: All possible strings of any length that can be formed from a given string K length words that can be formed from given characters without repetition Print all possible strings that can be made by placing spaces Print all possible strings that can be made by placing spaces Print all distinct integers that can be formed by K numbers from a given array of N numbers Number of ways in which the substring in range [L, R] can be formed using characters out of the range Check if a given string can be formed using characters of adjacent cells of a Matrix Find the numbers of strings that can be formed after processing Q queries Maximum number of strings that can be formed with given zeros and ones Find the count of numbers that can be formed using digits 3, 4 only and having length at max N.

Count of Distinct strings possible by inserting K characters in the original string Sum of all numbers that can be formed with permutations of n digits Count of substrings formed using a given set of characters only Count of non-palindromic strings of length M using given N characters Maximize length of the String by concatenating characters from an Array of Strings Count possible binary strings of length N without P consecutive 0s and Q consecutive 1s Find all the possible mappings of characters in a sorted order Count ways to place all the characters of two given strings alternately Count of distinct XORs formed by rearranging two Binary strings Number of balanced bracket expressions that can be formed from a string.

Load Comments. We use cookies to ensure you have the best browsing experience on our website.

## Replies to “Print keypad combinations code c”