Pojam leksikografski poredak je matematički pojam poznat pod imenima: leksički poredak, leksikografski (al) proizvod, abecedni red ili rječnički poredak.
Ovaj odjeljak će pokriti leksikografski poredak teme, njezinu definiciju i druge detaljne informacije. Nakon toga ćemo naučiti kako koristiti pojam leksikografskog reda u Java programski jezik .
Definiranje leksikografskog reda
Leksikografski poredak ili leksikografski u matematici je generalizacija abecednog niza rječnika na nizove poredanih simbola ili elemenata potpuno uređenog popisa. Pojam leksikografski poredak motiviran je riječju leksikon. Leksikon je skup riječi koji se koristi u nekim drugim jezicima i ima konvencionalni poredak. Stoga je leksikografski poredak način za formaliziranje reda riječi gdje je dan redoslijed temeljnih simbola.
U programiranju, leksikografski poredak je popularno poznat kao Redoslijed rječnika i koristi se za sortiranje niza nizova, usporedbu dva niza ili sortiranje elemenata niza. Postaje vrlo jednostavno sortirati elemente leksički. To je zato što leksikografski poredak ima nekoliko varijanti i generalizacija u kojima:
- Jedna je varijanta primjenjiva na nizove različitih duljina jer se prije razmatranja pojedinih elemenata uspoređuju duljine nizova.
- Druga varijanta se koristi u redoslijedu podskupova zadanog konačnog skupa. To čini dodjeljivanjem ukupnog reda konačnom skupu. Zatim se podskupovi pretvaraju u rastuće nizove na koje se primjenjuje leksikografski poredak.
- Generalizacija se odnosi na Kartezijev produkt niza djelomično uređenih skupova, a takav niz je totalni poredak, ako i samo ako je svaki faktor Kartezijevog produkta uređen totalno.
Razumijevanje formalnog pojma leksikografskog reda
- Da bismo razumjeli formalni pojam leksikografskog reda:
- Počinje s konačnim skupom A, koji je poznat kao abeceda i potpuno je nizan. To nadalje znači da za a i b (bilo koja dva simbola koja su različita i nisu ista) u A, ili a
- Ovdje su riječi od A konačan niz simbola od A i uključuju riječi duljine 1 koje drže jedan simbol, riječi duljine 2 s dva simbola, a za riječi duljine tri to je 3, i tako dalje. S poštovanjem, također uključuje prazan niz ? ne držeći nikakve simbole. Stoga se leksikografski poredak za konačni skup A može opisati kao:
- Pretpostavimo, za dva različita svijeta iste duljine, a=a1a2…aki b=b1b2…bkje dano. Ovdje redoslijed dvije riječi ovisi o abecednom redu simbola na prvom mjestu i gdje dvije riječi variraju kada se broje od početka riječi, tj. zadovoljavaju uvjet a i
- Ako dvije riječi variraju u duljini, uobičajeni leksikografski poredak dodaje riječ kraće duljine prazninama na kraju sve dok obje riječi ne postanu iste duljine, a zatim se riječi uspoređuju.
Implementacija leksikografskog u Javi
Kao što je gore razmotreno, taj se leksikografski poredak može koristiti ili za usporedbu dva niza ili za sortiranje elemenata. Ovdje ćemo raspravljati o objema metodama i svaku ćemo implementirati.
Razvrstavanje elemenata u leksikografskom redu
Slaganje riječi po redu poznato je kao leksikografski poredak ili također poznat kao Redoslijed rječnika . To znači da se primjenom leksikografskog reda riječi poredaju abecednim redom prema njihovim sastavnim abecedama. Za sortiranje niza znakova prema leksikografskom redu, imamo sljedeće dvije metode:
Metoda 1: Primjena bilo koje metode sortiranja
Ispod je dan primjer koda koji će nam omogućiti da shvatimo kako možemo izvršiti sortiranje elemenata u leksikografskom redoslijedu:
public class Main { public static void main(String[] args) { String[] name = { 'John','Remo','Mixy','Julie','Ronny'}; int n = 5; System.out.println('Before Sorting'); for(int i = 0; i <n; i++) { system.out.println(name[i]); } for(int i="0;" < n-1; ++i) for (int j="i" + 1; 0) string temp="name[i];" name[i]="name[j];" name[j]="temp;" system.out.println('
after performing lexicographical order: '); n; pre> <p> <strong>Code Explanation:</strong> </p> <p>In the above code, we have created a class Main within which the main () method is created.</p> <ul> <li>A string has been initialized, holding some values to it, and each word will get printed as per for loop.</li> <li>Then, we have implemented the main logic within another for loop with the help of which we can form the lexicographical order of the words given.</li> <li>Finally, via for loop, the arranged words are printed on the screen.</li> </ul> <p> <strong>On executing the above example code, we got the following output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/62/lexicographical-order-java.webp" alt="Lexicographical Order Java"> <p>From the output, we can analyze that the given sequence of the words was not in alphabetical order but after applying the lexicographical order code, we can see that every word is sequenced now in alphabetical order.</p> <p> <strong>Method 2: Applying sort () function</strong> </p> <p>The sort () method is available in the Arrays class within the util package.</p> <p>Below is the example code given that will let us understand that how we can perform sorting on elements in Lexicographical order:</p> <pre> import java.io.*; import java.util.Arrays; class Main { public static void printArray(String str[]) { for (String string : str) System.out.print(string + ' '); System.out.println(); } public static void main(String[] args) { String arr[] = {'John','Harry','Emlie','Ronny','Julie','Mary' }; Arrays.sort(arr,String.CASE_INSENSITIVE_ORDER); printArray(arr); } } </pre> <p> <strong>On executing the above output, we got the below-shown output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/62/lexicographical-order-java-2.webp" alt="Lexicographical Order Java"> <h3>Comparing two strings using Lexicographical order in Java</h3> <p>For comparing two strings using Lexicographical order, we have the following two methods:</p> <p> <strong>Using compareTo () method</strong> </p> <p>Let's begin one by one:</p> <p> <strong>Using compareTo () method</strong> </p> <p>Below is an example implementation by which we can compare to strings lexicographically:</p> <pre> import java.lang.*; public class StringExample { public static void main(String[] args) { String str1 = 'String', str2 = 'Comparison'; int get_val = str1.compareTo(str2); if (get_val <0) { system.out.println('str1 is greater than str2'); } else if (get_val="=" 0) equal to less < pre> <p> <strong>Code Explanation:</strong> </p> <ul> <li>We have created a class StringExample where we have implemented the main () method.</li> <li>We have initialized two strings, i.e., str1 and str2.</li> <li>Next, using the compareTo () method, we have compared the strings str1 and str2.</li> <li>After it, if the get_val value is found less than 0, it means str1 is greater than str2.</li> <li>Else if the get_val value is equal to 0, it means both str1 and str2 strings are equal.</li> <li>Else, both the strings str1 is less than str2.</li> </ul> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/62/lexicographical-order-java-3.webp" alt="Lexicographical Order Java"> <p> <strong>By creating a user-defined function</strong> </p> <p>Below we have created a user-defined function using which we can compare two strings lexicographically. The code is as follows:</p> <pre> public class StringExample { public static void main(String[] args) { String firstString = 'Red'; String secondString = 'Red'; String thirdString = 'Green'; String fourthString = 'Yellow'; String fifthString = 'REdGreen'; System.out.println('Comparing two strings lexicographically by user defined function'); System.out.print('
Compairing firstString ('+firstString+') to the secondString ('+secondString+') returns: '); System.out.println(compareString(firstString, secondString)); System.out.print('
Compairing secondString ('+secondString+') to the thirdString ('+thirdString+') returns: '); System.out.println(compareString(secondString, thirdString)); System.out.print('
Compairing thirdString ('+thirdString+') to the fourthString ('+fourthString+') returns: '); System.out.println(compareString(thirdString, fourthString)); System.out.print('
Compairing fourthString ('+fourthString+') to the firstString ('+firstString+') returns: '); System.out.println(compareString(fourthString, firstString)); System.out.print('
Compairing firstString ('+firstString+') to the fifthString ('+fifthString+') returns: '); System.out.println(compareString(firstString, fifthString)); } public static int compareString(String str, String argString) { int lim= Math.min(str.length(), argString.length()); int k=0; while(k<lim) { if(str.charat(k)!="argString.charAt(k))" return (int) str.charat(k)- argstring.charat(k); } k++; str.length() - argstring.length(); < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/62/lexicographical-order-java-4.webp" alt="Lexicographical Order Java"> <p> <strong>Code Explanation:</strong> </p> <ul> <li>We have created a Java class where we have initialized five strings.</li> <li>Next, we have compared the first string with the second string, the second to the third-string, and so on..</li> <li>For making the comparison, we have created a user-defined function compareString () whereby comparing the length and each character of the strings, and we got the results.</li> </ul> <p>Therefore, in this way, we can make use of the lexicographical order in Java for performing such tasks.</p> <hr></lim)></pre></0)></pre></n;> Nakon izvršenja gornjeg izlaza, dobili smo dolje prikazani izlaz:
Usporedba dva niza pomoću leksikografskog reda u Javi
Za usporedbu dva niza pomoću leksikografskog reda, imamo sljedeće dvije metode:
Korištenje metode compareTo ().
Počnimo jedan po jedan:
Korištenje metode compareTo ().
Ispod je primjer implementacije pomoću kojeg možemo leksikografski usporediti nizove:
import java.lang.*; public class StringExample { public static void main(String[] args) { String str1 = 'String', str2 = 'Comparison'; int get_val = str1.compareTo(str2); if (get_val <0) { system.out.println(\'str1 is greater than str2\'); } else if (get_val="=" 0) equal to less < pre> <p> <strong>Code Explanation:</strong> </p> <ul> <li>We have created a class StringExample where we have implemented the main () method.</li> <li>We have initialized two strings, i.e., str1 and str2.</li> <li>Next, using the compareTo () method, we have compared the strings str1 and str2.</li> <li>After it, if the get_val value is found less than 0, it means str1 is greater than str2.</li> <li>Else if the get_val value is equal to 0, it means both str1 and str2 strings are equal.</li> <li>Else, both the strings str1 is less than str2.</li> </ul> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/62/lexicographical-order-java-3.webp" alt="Lexicographical Order Java"> <p> <strong>By creating a user-defined function</strong> </p> <p>Below we have created a user-defined function using which we can compare two strings lexicographically. The code is as follows:</p> <pre> public class StringExample { public static void main(String[] args) { String firstString = 'Red'; String secondString = 'Red'; String thirdString = 'Green'; String fourthString = 'Yellow'; String fifthString = 'REdGreen'; System.out.println('Comparing two strings lexicographically by user defined function'); System.out.print('
Compairing firstString ('+firstString+') to the secondString ('+secondString+') returns: '); System.out.println(compareString(firstString, secondString)); System.out.print('
Compairing secondString ('+secondString+') to the thirdString ('+thirdString+') returns: '); System.out.println(compareString(secondString, thirdString)); System.out.print('
Compairing thirdString ('+thirdString+') to the fourthString ('+fourthString+') returns: '); System.out.println(compareString(thirdString, fourthString)); System.out.print('
Compairing fourthString ('+fourthString+') to the firstString ('+firstString+') returns: '); System.out.println(compareString(fourthString, firstString)); System.out.print('
Compairing firstString ('+firstString+') to the fifthString ('+fifthString+') returns: '); System.out.println(compareString(firstString, fifthString)); } public static int compareString(String str, String argString) { int lim= Math.min(str.length(), argString.length()); int k=0; while(k<lim) { if(str.charat(k)!="argString.charAt(k))" return (int) str.charat(k)- argstring.charat(k); } k++; str.length() - argstring.length(); < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/62/lexicographical-order-java-4.webp" alt="Lexicographical Order Java"> <p> <strong>Code Explanation:</strong> </p> <ul> <li>We have created a Java class where we have initialized five strings.</li> <li>Next, we have compared the first string with the second string, the second to the third-string, and so on..</li> <li>For making the comparison, we have created a user-defined function compareString () whereby comparing the length and each character of the strings, and we got the results.</li> </ul> <p>Therefore, in this way, we can make use of the lexicographical order in Java for performing such tasks.</p> <hr></lim)></pre></0)>