Given a string of two characters and n distinct words of two characters. The task is to find if it is possible to arrange given words in such a way that the concatenated string has the given two character string as a substring. We can append a word multiple times.
Examples:
Input : str = "ya" words[] = {"ah", "oy", "to", "ha"} Output : YES We can join "oy" and then "ah", and then "ha" to form the string "oyahha" which contains the string "ya". So, the answer is "YES" Input : str[] = "ha" words[] = "ah" Output :YES The string "ahah" contains "ha" as a substring. Input : str = "hp" words[] = {"ht", "tp"| Output :NO We can't produce a string containing "hp" as a sub-string. Note that we can join "ht" and then "tp" producing "http", but it doesn't contain the "hp" as a sub-string.
If we look at the given examples carefully, we can see that our answer will be “YES” if any of the following conditions is true,
- str is equal to any one of the N words
- str is equal to reverse of any of the words.
- It first letter of str is equal to last letter of any of the given N strings and last letter is equal to the first letter of any of the given N strings.
Otherwise our output will always be NO.
Below is the implementation of the above approach.
C++
// CPP code to check if a two character string can // be made using given strings #include <bits/stdc++.h> using namespace std; // Function to check if str can be made using // given words bool makeAndCheckString(vector<string> words, string str) { int n = words.size(); bool first = false , second = false ; for ( int i = 0; i < n; i++) { // If str itself is present if (words[i] == str) return true ; // Match first character of str // with second of word and vice versa if (str[0] == words[i][1]) first = true ; if (str[1] == words[i][0]) second = true ; // If both characters found. if (first && second) return true ; } return false ; } // Driver Code int main() { string str = "ya" ; vector<string> words = { "ah" , "oy" , "to" , "ha" }; if (makeAndCheckString(words, str)) cout << "Yes" ; else cout << "No" ; return 0; } |
Java
// Java code to check if a two character string can // be made using given strings import java.util.*; class GFG { // Function to check if str can be made using // given words static boolean makeAndCheckString(Vector<String> words, String str) { int n = words.size(); boolean first = false , second = false ; for ( int i = 0 ; i < n; i++) { // If str itself is present if (words.get(i) == str) return true ; // Match first character of str // with second of word and vice versa if (str.charAt( 0 ) == words.get(i).charAt( 1 )) first = true ; if (str.charAt( 1 ) == words.get(i).charAt( 0 )) second = true ; // If both characters found. if (first && second) return true ; } return false ; } // Driver Code public static void main(String[] args) { String str = "ya" ; String[] array = { "ah" , "oy" , "to" , "ha" }; Vector<String> words = new Vector<String>(Arrays.asList(array)); if (makeAndCheckString(words, str)) System.out.println( "Yes" ); else System.out.println( "No" ); } } // This code is contributed by 29AjayKumar |
Python3
# Python3 code to check if a two character string can # be made using given strings # Function to check if str can be made using # given words def makeAndCheckString(words, str ): n = len (words) first = second = False for i in range (n): # If str itself is present if words[i] = = str : return True # Match first character of str # with second of word and vice versa if str [ 0 ] = = words[i][ 1 ]: first = True if str [ 1 ] = = words[i][ 0 ]: second = True # If both characters found. if first and second: return True return False # Driver Code str = 'ya' words = [ 'ah' , 'oy' , 'to' , 'ha' ] if makeAndCheckString(words, str ): print ( 'YES' ) else : print ( 'NO' ) # This code is contributed # by SamyuktaSHegde |
C#
// C# code to check if a two character string can // be made using given strings using System; using System.Collections.Generic; class GFG { // Function to check if str can be made using // given words static bool makeAndCheckString(List<String> words, String str) { int n = words.Count; bool first = false , second = false ; for ( int i = 0; i < n; i++) { // If str itself is present if (words[i] == str) return true ; // Match first character of str // with second of word and vice versa if (str[0] == words[i][1]) first = true ; if (str[1] == words[i][0]) second = true ; // If both characters found. if (first && second) return true ; } return false ; } // Driver Code public static void Main(String[] args) { String str = "ya" ; String[] array = { "ah" , "oy" , "to" , "ha" }; List<String> words = new List<String>(array); if (makeAndCheckString(words, str)) Console.WriteLine( "Yes" ); else Console.WriteLine( "No" ); } } // This code is contributed by Princi Singh |
PHP
<?php // PHP code to check if a two character string can // be made using given strings // Function to check if str can be made using // given words function makeAndCheckString( $words , $str ) { $n = sizeof( $words ) ; $first = false ; $second = false; for ( $i = 0; $i < $n ; $i ++) { // If str itself is present if ( $words [ $i ] == $str ) return true; // Match first character of str // with second of word and vice versa if ( $str [0] == $words [ $i ][1]) $first = true; if ( $str [1] == $words [ $i ][0]) $second = true; // If both characters found. if ( $first && $second ) return true; } return false; } // Driver Code $str = "ya" ; $words = array ( "ah" , "oy" , "to" , "ha" ) ; if (makeAndCheckString( $words , $str )) echo "Yes" ; else echo "No" ; // This code is contributed by Ryuga ?> |
Output:
YES
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