Sort an array of strings lexicographically based on prefix
Given an array of strings arr[] of size N, the task is to sort the array of strings in lexicographical order and if while sorting for any two string A and string B, if string A is prefix of string B then string B should come in the sorted order.
Examples:
Input: arr[] = {“sun”, “moon”, “mock”}
Output:
mock
moon
sun
Explanation:
The lexicographical sorting is mock, moon, and sun.Input: arr[] = {“Beginner”, “Beginnerfor”, “w3wiki”}
Output:
w3wiki
Beginnerfor
Beginner
Approach: The idea is to sort the given array of strings using the inbuilt sort function using the below comparator function. The comparator function used to check if any string occurs as a substring in another string using compare() function in C++ then, it should arrange them in decreasing order of their length.
C++
bool my_compare(string a, string b) { // If any string is a substring then // return the size with greater length if (a.compare(0, b.size(), b) == 0 || b.compare(0, a.size(), a) == 0) return a.size() > b.size(); // Else return lexicographically // smallest string else return a < b; } |
Java
public static boolean my_compare(String a, String b) { // If any string is a substring then // return the size with greater length if (a.compareTo(b) == 0 || b.compareTo(a) == 0 ) return a.length() > b.length(); // Else return lexicographically // smallest string else { if (a.length() < b.length()) return true ; } return false ; } // This code is contributed by akashish__ |
Python3
def my_compare(a, b): # If any string is a substring then # return the size with greater length if (a.compare( 0 , b.length, b) is 0 or b.compare( 0 , a.length, a) is 0 ): return a.length > b.length; # Else return lexicographically # smallest string else : return a < b; # This code is contributed by akashish__ |
C#
// C# implementation of the approach using System; using System.Collections.Generic; public static bool my_compare( string a, string b) { // If any string is a substring then // return the size with greater length if (a.CompareTo(b) == 0 || b.CompareTo(a) == 0) return a.Length > b.Length; // Else return lexicographically // smallest string else { if (a.Length < b.Length) return true ; } return false ; } // This code is contributed by sanjoy_62. |
Javascript
function my_compare(a,b) { // If any string is a substring then // return the size with greater length if (a.compare(0, b.length, b) == 0 || b.compare(0, a.length, a) == 0) return a.length > b.length; // Else return lexicographically // smallest string else return a < b; } // This code is contributed by ksam24000. |
Below is the implementation of the above approach:
C++
// C++ program for the above approach #include <bits/stdc++.h> using namespace std; // Function to print the vector void Print(vector<string> v) { for ( auto i : v) cout << i << endl; } // Comparator function to sort the // array of string wrt given conditions bool my_compare(string a, string b) { // Check if a string is present as // prefix in another string, then // compare the size of the string // and return the larger size if (a.compare(0, b.size(), b) == 0 || b.compare(0, a.size(), a) == 0) return a.size() > b.size(); // Else return lexicographically // smallest string else return a < b; } // Driver Code int main() { // GIven vector of strings vector<string> v = { "batman" , "bat" , "apple" }; // Calling Sort STL with my_compare // function passed as third parameter sort(v.begin(), v.end(), my_compare); // Function call to print the vector Print(v); return 0; } |
Java
/*package whatever //do not write package name here */ import java.io.*; import java.lang.*; import java.util.*; class GFG { public static int comp(String a, int s, int e, String b) { if (a.length() >= e && b.length() >= e) { for ( int i = s; i < e; i++) { if (a.charAt(i) != b.charAt(i)) return - 1 ; } } else return - 1 ; return 0 ; } // Function to print the vector public static void Print(List<String> v) { for (String i : v) System.out.println(i); } public static void main(String[] args) { // GIven vector of strings List<String> v = new ArrayList<String>(); v.add( "batman" ); v.add( "bat" ); v.add( "apple" ); // Calling Sort STL with my_compare // function passed as third parameter Collections.sort(v, new Comparator<String>() { @Override public int compare( final String a, String b) { // Check if a string is present as // prefix in another string, then // compare the size of the string // and return the larger size if (comp(a, 0 , b.length(), b) == 0 || comp(b, 0 , a.length(), a) == 0 ) { if (a.length() > b.length()) { return 1 ; } else return 1 ; } // Else return lexicographically // smallest string else { if (a.length() < b.length()) return - 1 ; } return - 1 ; } }); // Function call to print the vector Print(v); } } // This code is contributed by akashish__ |
Python3
# Function to print the vector def Print (v): print (v) def comp(a,s,e,b): if ( len (a) > = e and len (b) > = e): for i in range (s,e): if (a[i] is not b[i]): return - 1 else : return - 1 return 0 # Comparator function to sort the # array of string wrt given conditions def sort(v,lst): a = v[ 1 ] b = v[ 0 ] c = v[ 2 ] # returning lexicographically smallest string if (c<a and c<b): lst.append(c) # Check if a string is present as # prefix in another string, then # compare the size of the string # and return the larger size if (comp(a, 0 , len (b), b) is 0 or comp(b, 0 , len (a), a) is 0 ): if ( len (a)> len (b)): lst.append(a) lst.append(b) else : lst.append(b) lst.append(a) # Driver Code # GIven vector of strings v = [ "batman" , "bat" , "apple" ] # Calling Sort STL with my_compare # function passed as third parameter lst = [] sort(v,lst) # Function call to print the vector Print (lst) # This code is contributed by akashish__ |
C#
using System; using System.Collections.Generic; public class GFG { // Function to print the public static void Print(List< string > v) { for ( int i = 0; i < v.Count; i++) { Console.WriteLine(v[i]); } } public static int comp(String a, int s, int e, String b) { if (a.Length >= e && b.Length >= e) { for ( int i = s; i < e; i++) { if (a[i] != b[i]) return -1; } } else return -1; return 0; } // Comparator function to sort the // array of string wrt given conditions public static int compare(String a, String b) { // Check if a string is present as // prefix in another string, then // compare the size of the string // and return the larger size if (comp(a, 0, b.Length, b) == 0 || comp(b, 0, a.Length, a) == 0) { if (a.Length > b.Length) { return -1; } else return 1; } // Else return lexicographically // smallest string else { if (a.Length > b.Length) return 1; } return -1; } static public void Main() { // Driver Code // Given List of strings List< string > v = new List< string >(); v.Add( "batman" ); v.Add( "bat" ); v.Add( "apple" ); // Calling Sort STL with my_compare // function passed as third parameter v.Sort(compare); // Function call to print the vector Print(v); } } // This code is contributed by akashish__ |
Javascript
<script> // Function to print the vector function Print(v) { console.log(v); } function comp(a,s,e,b) { if (a.length >= e && b.length >= e) { for (let i = s; i < e; i++) { if (a[i] != b[i]) return -1; } } else return -1; return 0; } // Comparator function to sort the // array of string wrt given conditions function compare(a,b) { // Check if a string is present as // prefix in another string, then // compare the size of the string // and return the larger size if (comp(a, 0, b.length, b) == 0 || comp(b, 0, a.length, a) == 0) { if (a.length > b.length) { return -1; } else return -1; } // Else return lexicographically // smallest string else { if (a.length < b.length) return 1; } return 1; } // Driver Code // GIven vector of strings v = [ "batman" , "bat" , "apple" ]; // Calling Sort STL with my_compare // function passed as third parameter v.sort(compare); // Function call to print the vector Print(v); // This code is contributed by akashish__ </script> |
apple batman bat
Time Complexity: O(N*log N)
Auxiliary Space: O(1)