# Longest common anagram subsequence from N strings

Given N strings. Find the longest possible subsequence from each of these N strings such that they are anagram to each other. The task is to print the lexicographically largest subsequence among all the subsequences.

Examples:

Input: s[] = { geeks, esrka, efrsk }
Output: ske
First string has “eks”, Second string has “esk”, third string has “esk”. These three are anagrams. “ske” is lexoigrapically large.

Input: string s[] = { loop, lol, olive }
Output: ol

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach :

• Make a 2-D array of n*26 to store the frequency of each character in string.
• After making frequency array, traverse in reverse direction for each digit and find the string which has the minimum characters of this type.
• After complete reverse traversal, print the character that occurs the minimum number of times since it gives the lexicographically largest string.

Below is the implementation of the above approach.

## C++

 `// C++ program to find longest possible ` `// subsequence anagram of N strings. ` `#include ` `using` `namespace` `std; ` `const` `int` `MAX_CHAR = 26; ` ` `  `// function to store frequency of ` `// each character in each string ` `void` `frequency(``int` `fre[][MAX_CHAR], string s[], ``int` `n) ` `{ ` `    ``for` `(``int` `i = 0; i < n; i++) { ` `        ``string str = s[i]; ` `        ``for` `(``int` `j = 0; j < str.size(); j++)  ` `            ``fre[i][str[j] - ``'a'``]++;         ` `    ``} ` `} ` ` `  `// function to Find longest possible sequence of N ` `// strings which is anagram to each other ` `void` `LongestSequence(``int` `fre[][MAX_CHAR], ``int` `n) ` `{ ` `    ``// to get lexicographical largest sequence. ` `    ``for` `(``int` `i = MAX_CHAR-1; i >= 0; i--) { ` ` `  `        ``// find minimum of that character ` `        ``int` `mi = fre[i]; ` `        ``for` `(``int` `j = 1; j < n; j++)  ` `            ``mi = min(fre[j][i], mi);         ` ` `  `        ``// print that character ` `        ``// minimum number of times ` `        ``while` `(mi--)  ` `            ``cout << (``char``)(``'a'` `+ i);         ` `    ``} ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` ` `  `    ``string s[] = { ``"loo"``, ``"lol"``, ``"olive"` `}; ` `    ``int` `n = ``sizeof``(s)/``sizeof``(s); ` ` `  `    ``// to strore frequency of each character in each string ` `    ``int` `fre[n] = { 0 }; ` ` `  `    ``// to get frequency of each character ` `    ``frequency(fre, s, n); ` ` `  `    ``// function call ` `    ``LongestSequence(fre, n); ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java program to find longest ` `// possible subsequence anagram ` `// of N strings. ` `class` `GFG ` `{  ` `final` `int` `MAX_CHAR = ``26``; ` ` `  `// function to store frequency  ` `// of each character in each  ` `// string ` `static` `void` `frequency(``int` `fre[][], ` `                      ``String s[], ``int` `n) ` `{ ` `    ``for` `(``int` `i = ``0``; i < n; i++)  ` `    ``{ ` `        ``String str = s[i]; ` `        ``for` `(``int` `j = ``0``; ` `                 ``j < str.length(); j++)  ` `            ``fre[i][str.charAt(j) - ``'a'``]++;      ` `    ``} ` `} ` ` `  `// function to Find longest  ` `// possible sequence of N ` `// strings which is anagram  ` `// to each other ` `static` `void` `LongestSequence(``int` `fre[][],  ` `                            ``int` `n) ` `{ ` `    ``// to get lexicographical  ` `    ``// largest sequence. ` `    ``for` `(``int` `i = ``24``; i >= ``0``; i--) ` `    ``{ ` ` `  `        ``// find minimum of ` `        ``// that character ` `        ``int` `mi = fre[``0``][i]; ` `        ``for` `(``int` `j = ``1``; j < n; j++)  ` `            ``mi = Math.min(fre[j][i], mi);      ` ` `  `        ``// print that character ` `        ``// minimum number of times ` `        ``while` `(mi--!=``0``)  ` `            ``System.out.print((``char``)(``'a'` `+ i));      ` `    ``} ` `} ` ` `  `// Driver code ` `public` `static` `void` `main(String args[]) ` `{ ` ` `  `    ``String s[] = { ``"loo"``, ``"lol"``, ``"olive"` `}; ` `    ``int` `n = s.length; ` ` `  `    ``// to strore frequency of each ` `    ``// character in each string ` `    ``int` `fre[][] = ``new` `int``[n][``26``] ; ` ` `  `    ``// to get frequency  ` `    ``// of each character ` `    ``frequency(fre, s, n); ` ` `  `    ``// function call ` `    ``LongestSequence(fre, n); ` `} ` `} ` ` `  `// This code is contributed ` `// by Arnab Kundu `

## Python3

 `# Python3 program to find longest possible  ` `# subsequence anagram of N strings.  ` ` `  `# Function to store frequency of  ` `# each character in each string  ` `def` `frequency(fre, s, n):  ` ` `  `    ``for` `i ``in` `range``(``0``, n):  ` `        ``string ``=` `s[i]  ` `        ``for` `j ``in` `range``(``0``, ``len``(string)):  ` `            ``fre[i][``ord``(string[j]) ``-` `ord``(``'a'``)] ``+``=` `1`         ` `  `# Function to Find longest possible sequence   ` `# of N strings which is anagram to each other  ` `def` `LongestSequence(fre, n):  ` ` `  `    ``# to get lexicographical largest sequence.  ` `    ``for` `i ``in` `range``(MAX_CHAR``-``1``, ``-``1``, ``-``1``):  ` ` `  `        ``# find minimum of that character  ` `        ``mi ``=` `fre[``0``][i]  ` `        ``for` `j ``in` `range``(``1``, n):  ` `            ``mi ``=` `min``(fre[j][i], mi)          ` ` `  `        ``# print that character  ` `        ``# minimum number of times  ` `        ``while` `mi:  ` `            ``print``(``chr``(``ord``(``'a'``) ``+` `i), end ``=` `"") ` `            ``mi ``-``=` `1` `     `  `# Driver code  ` `if` `__name__ ``=``=` `"__main__"``: ` ` `  `    ``s ``=` `[``"loo"``, ``"lol"``, ``"olive"``]  ` `    ``n ``=` `len``(s) ` `    ``MAX_CHAR ``=` `26` ` `  `    ``# to strore frequency of each  ` `    ``# character in each string  ` `    ``fre ``=` `[[``0` `for` `i ``in` `range``(``26``)]  ` `              ``for` `j ``in` `range``(n)]  ` ` `  `    ``# To get frequency of each character  ` `    ``frequency(fre, s, n)  ` ` `  `    ``# Function call  ` `    ``LongestSequence(fre, n)  ` ` `  `# This code is contributed by  ` `# Rituraj Jain `

## C#

 `// c# program to find longest  ` `// possible subsequence anagram  ` `// of N strings.  ` `using` `System; ` ` `  `class` `GFG ` `{ ` `public` `readonly` `int` `MAX_CHAR = 26; ` ` `  `// function to store frequency  ` `// of each character in each  ` `// string  ` `public` `static` `void` `frequency(``int``[,] fre,  ` `                             ``string``[] s, ``int` `n) ` `{ ` `    ``for` `(``int` `i = 0; i < n; i++) ` `    ``{ ` `        ``string` `str = s[i]; ` `        ``for` `(``int` `j = 0;  ` `                 ``j < str.Length; j++) ` `        ``{ ` `            ``fre[i, str[j] - ``'a'``]++; ` `        ``} ` `    ``} ` `} ` ` `  `// function to Find longest  ` `// possible sequence of N  ` `// strings which is anagram  ` `// to each other  ` `public` `static` `void` `LongestSequence(``int``[, ] fre,  ` `                                   ``int` `n) ` `{ ` `    ``// to get lexicographical  ` `    ``// largest sequence.  ` `    ``for` `(``int` `i = 24; i >= 0; i--) ` `    ``{ ` ` `  `        ``// find minimum of  ` `        ``// that character  ` `        ``int` `mi = fre[0, i]; ` `        ``for` `(``int` `j = 1; j < n; j++) ` `        ``{ ` `            ``mi = Math.Min(fre[j, i], mi); ` `        ``} ` ` `  `        ``// print that character  ` `        ``// minimum number of times  ` `        ``while` `(mi--!=0) ` `        ``{ ` `            ``Console.Write((``char``)(``'a'` `+ i)); ` `        ``} ` `    ``} ` `} ` ` `  `// Driver code  ` `public` `static` `void` `Main(``string``[] args) ` `{ ` ` `  `    ``string``[] s = ``new` `string``[] {``"loo"``, ``"lol"``, ``"olive"``}; ` `    ``int` `n = s.Length; ` ` `  `    ``// to strore frequency of each  ` `    ``// character in each string  ` `    ``int``[, ] fre = ``new` `int``[n, 26]; ` ` `  `    ``// to get frequency  ` `    ``// of each character  ` `    ``frequency(fre, s, n); ` ` `  `    ``// function call  ` `    ``LongestSequence(fre, n); ` `} ` `} ` ` `  `// This code is contributed by Shrikanth13 `

Output:

```ol
```

My Personal Notes arrow_drop_up pawanasipugmailcom

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Article Tags :
Practice Tags :

Be the First to upvote.

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.