Grupės perkelta eilutė
Atsižvelgiant į eilučių masyvą (visos mažosios raidės), užduotis yra sugrupuoti jas taip, kad visos grupės eilutės būtų viena kitos pakeistos versijos.
Dvi stygos s1 ir s2 vadinami perkeliamais, jei tenkinamos šios sąlygos:
- s1.ilgis yra lygus s2.ilgis
- s1[i] yra lygus s2[i] + m visiems 1 <= i <= s1.length for a pastovus sveikasis skaičius m. Laikykite, kad poslinkis yra ciklinis, tai yra, jei s2[i] + m > 'z', tada prasideda nuo "a" arba jei s2[i] + m < 'a' then start from 'z'.
Pavyzdžiai:
Įvestis: arr[] = ['acd' "dfg" "wyz" "yab" "mop" "bdfh" "a" "x" "moqs"]
Išvestis: [ [ 'acd' 'dfg' 'wyz' 'yab' 'mop'] ['bdfh' 'moqs'] ['a' 'x'] ]
Paaiškinimas: Visos perkeltos eilutės yra sugrupuotos.
Įvestis: arr = ['geek' 'for' 'geeks']
Išvestis: [['už'] ['geek'] ['geeks']]
Metodas: maišos žemėlapio naudojimas
C++Idėja yra sukurti unikalų maišos kiekvienai grupei pagal normalizuojantis stygos. Čia normalizuojantis reiškia, kad kiekvienos eilutės pirmasis simbolis lygus „a“, apskaičiuojant reikalingą skaičių pamainomis ir vienodai taikydami jį visiems simboliams ciklinė mada .
Pavyzdys: s = "dca" shifts = "d" - "a" = 3
normalizuoti simboliai: "d" - 3 = "a" "c" - 3 = "z" ir "a" - 3 = "x"
normalizuota eilutė = 'azx'The normalizuota eilutė (hash) reiškia poslinkio modelis taip, kad to paties rašto eilutės turėtų tą pačią maišą. Mes naudojame maišos žemėlapį, kad galėtume sekti šias maišas ir susieti jas su atitinkamomis grupėmis. Kiekvienai eilutei apskaičiuojame maišą ir naudojame jį, kad sukurtume naują grupę arba įtrauktume eilutę prie esamos grupės per vieną apėjimą.
// C++ program to print groups of shifted strings // together using Hash Map #include #include #include using namespace std ; // Function to generate hash by shifting and equating // the first character string getHash ( string s ) { // Calculate the shift needed to normalize the string int shifts = s [ 0 ] - 'a' ; for ( char & ch : s ) { // Adjust each character by the shift ch = ch - shifts ; // Wrap around if the character goes below 'a' if ( ch < 'a' ) ch += 26 ; } return s ; } // Function to group shifted string together vector < vector < string >> groupShiftedString ( vector < string > & arr ) { vector < vector < string >> res ; // Maps hash to index in result unordered_map < string int > mp ; for ( string s : arr ) { // Generate hash representing the shift pattern string hash = getHash ( s ); // If new hash create a new group if ( mp . find ( hash ) == mp . end ()) { mp [ hash ] = res . size (); res . push_back ({}); } // Add string to its group res [ mp [ hash ]]. push_back ( s ); } return res ; } int main () { vector < string > arr = { 'acd' 'dfg' 'wyz' 'yab' 'mop' 'bdfh' 'a' 'x' 'moqs' }; vector < vector < string >> groups = groupShiftedString ( arr ); for ( vector < string > & group : groups ) { for ( string & s : group ) { cout < < s < < ' ' ; } cout < < endl ; } return 0 ; }
Java // Java program to print groups of shifted strings // together using Hash Map import java.util.* ; class GfG { // Function to generate hash by shifting and equating the // first character static String getHash ( String s ) { // Calculate the shift needed to normalize the string int shifts = s . charAt ( 0 ) - 'a' ; char [] chars = s . toCharArray (); for ( int i = 0 ; i < chars . length ; i ++ ) { // Adjust each character by the shift chars [ i ] = ( char ) ( chars [ i ] - shifts ); // Wrap around if the character goes below 'a' if ( chars [ i ] < 'a' ) chars [ i ] += 26 ; } return new String ( chars ); } // Function to group shifted strings together static ArrayList < ArrayList < String >> groupShiftedString ( String [] arr ) { ArrayList < ArrayList < String >> res = new ArrayList <> (); // Maps hash to index in result HashMap < String Integer > mp = new HashMap <> (); for ( String s : arr ) { // Generate hash representing the shift pattern String hash = getHash ( s ); // If new hash create a new group if ( ! mp . containsKey ( hash )) { mp . put ( hash res . size ()); res . add ( new ArrayList <> ()); } // Add string to its group res . get ( mp . get ( hash )). add ( s ); } return res ; } public static void main ( String [] args ) { String [] arr = { 'acd' 'dfg' 'wyz' 'yab' 'mop' 'bdfh' 'a' 'x' 'moqs' }; ArrayList < ArrayList < String >> groups = groupShiftedString ( arr ); for ( ArrayList < String > group : groups ) { for ( String s : group ) { System . out . print ( s + ' ' ); } System . out . println (); } } }
Python # Python program to print groups of shifted strings # together using Hash Map # Function to generate hash by shifting and equating the first character def getHash ( s ): # Calculate the shift needed to normalize the string shifts = ord ( s [ 0 ]) - ord ( 'a' ) hashVal = [] for ch in s : # Adjust each character by the shift newCh = chr ( ord ( ch ) - shifts ) # Wrap around if the character goes below 'a' if newCh < 'a' : newCh = chr ( ord ( newCh ) + 26 ) hashVal . append ( newCh ) return '' . join ( hashVal ) # Function to group shifted strings together def groupShiftedString ( arr ): res = [] # Maps hash to index in result mp = {} for s in arr : # Generate hash representing the shift pattern hashVal = getHash ( s ) # If new hash create a new group if hashVal not in mp : mp [ hashVal ] = len ( res ) res . append ([]) # Add string to its group res [ mp [ hashVal ]] . append ( s ) return res if __name__ == '__main__' : arr = [ 'acd' 'dfg' 'wyz' 'yab' 'mop' 'bdfh' 'a' 'x' 'moqs' ] groups = groupShiftedString ( arr ) for group in groups : print ( ' ' . join ( group ))
C# // C# program to print groups of shifted strings // together using Hash Map using System ; using System.Collections.Generic ; class GfG { // Function to generate hash by shifting and equating the first character static string getHash ( string s ) { // Calculate the shift needed to normalize the string int shifts = s [ 0 ] - 'a' ; char [] chars = s . ToCharArray (); for ( int i = 0 ; i < chars . Length ; i ++ ) { // Adjust each character by the shift chars [ i ] = ( char )( chars [ i ] - shifts ); // Wrap around if the character goes below 'a' if ( chars [ i ] < 'a' ) chars [ i ] += ( char ) 26 ; } return new string ( chars ); } // Function to group shifted strings together static List < List < string >> groupShiftedString ( string [] arr ) { List < List < string >> res = new List < List < string >> (); // Maps hash to index in result Dictionary < string int > mp = new Dictionary < string int > (); foreach ( string s in arr ) { // Generate hash representing the shift pattern string hash = getHash ( s ); // If new hash create a new group if ( ! mp . ContainsKey ( hash )) { mp [ hash ] = res . Count ; res . Add ( new List < string > ()); } // Add string to its group res [ mp [ hash ]]. Add ( s ); } return res ; } static void Main ( string [] args ) { string [] arr = { 'acd' 'dfg' 'wyz' 'yab' 'mop' 'bdfh' 'a' 'x' 'moqs' }; var groups = groupShiftedString ( arr ); foreach ( var group in groups ) { Console . WriteLine ( string . Join ( ' ' group )); } } }
JavaScript // JavaScript program to print groups of shifted strings // together using Hash Map // Function to generate hash by shifting and equating the first character function getHash ( s ) { // Calculate the shift needed to normalize the string const shifts = s . charCodeAt ( 0 ) - 'a' . charCodeAt ( 0 ); let chars = []; for ( let ch of s ) { // Adjust each character by the shift let newChar = String . fromCharCode ( ch . charCodeAt ( 0 ) - shifts ); // Wrap around if the character goes below 'a' if ( newChar < 'a' ) newChar = String . fromCharCode ( newChar . charCodeAt ( 0 ) + 26 ); chars . push ( newChar ); } return chars . join ( '' ); } // Function to group shifted strings together function groupShiftedString ( arr ) { const res = []; // Maps hash to index in result const mp = new Map (); for ( let s of arr ) { // Generate hash representing the shift pattern const hash = getHash ( s ); // If new hash create a new group if ( ! mp . has ( hash )) { mp . set ( hash res . length ); res . push ([]); } // Add string to its group res [ mp . get ( hash )]. push ( s ); } return res ; } // Driver Code const arr = [ 'acd' 'dfg' 'wyz' 'yab' 'mop' 'bdfh' 'a' 'x' 'moqs' ]; const groups = groupShiftedString ( arr ); groups . forEach ( group => console . log ( group . join ( ' ' )));
Išvestis
acd dfg wyz yab mop bdfh moqs a x
Laiko sudėtingumas: O(n*k) kur n yra eilučių masyvo ilgis, o k yra maksimalus eilutės ilgis eilučių masyve.
Pagalbinė erdvė: O(n*k) blogiausiu atveju kiekvienai įvesties eilutei galime sugeneruoti n skirtingų maišos eilučių. Taigi maišos žemėlapyje gavome n skirtingų įrašų, kurių kiekvienas yra k ar mažesnis.
