전화번호부 구현
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#practiceLinkDiv { 표시: 없음 !중요; } 전화번호부에 존재하는 연락처 목록이 제공됩니다. 작업은 전화번호부에 대한 검색 쿼리를 구현하는 것입니다. 문자열 '에 대한 검색어 str ’는 접두사가 ‘로 붙은 모든 연락처를 표시합니다. str '. 검색 기능의 특별한 속성 중 하나는 사용자가 연락처 목록에서 연락처를 검색할 때 사용자가 각 문자를 입력한 후 제안 사항(입력한 문자열로 접두사가 있는 연락처)이 표시된다는 것입니다.
메모: 목록의 연락처는 소문자 알파벳으로만 구성됩니다. 예:
Input : contacts [] = {gforgeeks geeksquiz } Query String = gekk Output : Suggestions based on 'g' are geeksquiz gforgeeks Suggestions based on 'ge' are geeksquiz No Results Found for 'gek' No Results Found for 'gekk' 권장 사항: 해결해 보세요. 관행 먼저 솔루션으로 넘어가기 전에
전화번호부는 다음을 사용하여 효율적으로 구현할 수 있습니다. 트라이 데이터 구조. 모든 연락처를 Trie에 삽입합니다. 일반적으로 Trie에 대한 검색 쿼리는 문자열이 trie에 존재하는지 여부를 확인하는 것이지만 이 경우 각 접두사 'str'이 있는 모든 문자열을 찾으라는 요청을 받습니다. 이는 다음을 수행하는 것과 동일합니다. 그래프의 DFS 순회 . Trie 노드에서 인접한 Trie 노드를 방문하고 더 이상 인접한 노드가 없을 때까지 이 작업을 반복적으로 수행합니다. 이 재귀 함수는 두 개의 인수를 사용합니다. 하나는 방문 중인 현재 Trie 노드를 가리키는 Trie 노드이고 다른 하나는 'str'이라는 접두사를 사용하여 지금까지 발견된 문자열을 저장하는 문자열입니다. 각 Trie 노드는 노드가 연락처(단어)의 끝을 나타내는 경우 true인 부울 변수 'isLast'를 저장합니다.
// This function displays all words with given // prefix. 'node' represents last node when // path from root follows characters of 'prefix'. displayContacts (TreiNode node string prefix) If (node.isLast is true) display prefix // finding adjacent nodes for each character ‘i’ in lower case Alphabets if (node.child[i] != NULL) displayContacts(node.child[i] prefix+i)
사용자는 문자열을 문자별로 입력하며 입력한 모든 문자 뒤에 접두사가 형성된 제안을 표시해야 합니다. 따라서 형성된 문자열로 시작하는 접두어를 찾는 한 가지 방법은 접두어가 Trie에 존재하는지 확인한 다음, 그렇다면 displayContacts() 함수를 호출하는 것입니다. 이 접근 방식에서는 입력된 모든 문자 후에 해당 문자열이 Trie에 존재하는지 확인합니다. 계속해서 확인하는 대신 포인터를 유지할 수 있습니다. 이전노드 '는 사용자가 마지막으로 입력한 문자에 해당하는 TrieNode를 가리키는데 이제 사용자가 다른 문자를 입력하면 Trie에 존재하는지 확인하기 위해 'prevNode'에 대한 하위 노드를 확인해야 합니다. 새 접두사가 Trie에 없으면 '접두사' 뒤에 문자를 입력하여 형성된 모든 문자열을 Trie에서도 찾을 수 없습니다. 따라서 접두사를 하나씩 생성하는 데 사용되는 루프를 중단하고 나머지 모든 문자에 대해 '결과를 찾을 수 없음'을 인쇄합니다.
C++ // C++ Program to Implement a Phone // Directory Using Trie Data Structure #include using namespace std ; struct TrieNode { // Each Trie Node contains a Map 'child' // where each alphabet points to a Trie // Node. // We can also use a fixed size array of // size 256. unordered_map < char TrieNode *> child ; // 'isLast' is true if the node represents // end of a contact bool isLast ; // Default Constructor TrieNode () { // Initialize all the Trie nodes with NULL for ( char i = 'a' ; i <= 'z' ; i ++ ) child [ i ] = NULL ; isLast = false ; } }; // Making root NULL for ease so that it doesn't // have to be passed to all functions. TrieNode * root = NULL ; // Insert a Contact into the Trie void insert ( string s ) { int len = s . length (); // 'itr' is used to iterate the Trie Nodes TrieNode * itr = root ; for ( int i = 0 ; i < len ; i ++ ) { // Check if the s[i] is already present in // Trie TrieNode * nextNode = itr -> child [ s [ i ]]; if ( nextNode == NULL ) { // If not found then create a new TrieNode nextNode = new TrieNode (); // Insert into the Map itr -> child [ s [ i ]] = nextNode ; } // Move the iterator('itr') to point to next // Trie Node itr = nextNode ; // If its the last character of the string 's' // then mark 'isLast' as true if ( i == len - 1 ) itr -> isLast = true ; } } // This function simply displays all dictionary words // going through current node. String 'prefix' // represents string corresponding to the path from // root to curNode. void displayContactsUtil ( TrieNode * curNode string prefix ) { // Check if the string 'prefix' ends at this Node // If yes then display the string found so far if ( curNode -> isLast ) cout < < prefix < < endl ; // Find all the adjacent Nodes to the current // Node and then call the function recursively // This is similar to performing DFS on a graph for ( char i = 'a' ; i <= 'z' ; i ++ ) { TrieNode * nextNode = curNode -> child [ i ]; if ( nextNode != NULL ) displayContactsUtil ( nextNode prefix + ( char ) i ); } } // Display suggestions after every character enter by // the user for a given query string 'str' void displayContacts ( string str ) { TrieNode * prevNode = root ; string prefix = '' ; int len = str . length (); // Display the contact List for string formed // after entering every character int i ; for ( i = 0 ; i < len ; i ++ ) { // 'prefix' stores the string formed so far prefix += ( char ) str [ i ]; // Get the last character entered char lastChar = prefix [ i ]; // Find the Node corresponding to the last // character of 'prefix' which is pointed by // prevNode of the Trie TrieNode * curNode = prevNode -> child [ lastChar ]; // If nothing found then break the loop as // no more prefixes are going to be present. if ( curNode == NULL ) { cout < < ' n No Results Found for ' < < prefix < < ' n ' ; i ++ ; break ; } // If present in trie then display all // the contacts with given prefix. cout < < ' n Suggestions based on ' < < prefix < < 'are ' ; displayContactsUtil ( curNode prefix ); // Change prevNode for next prefix prevNode = curNode ; } // Once search fails for a prefix we print // 'Not Results Found' for all remaining // characters of current query string 'str'. for (; i < len ; i ++ ) { prefix += ( char ) str [ i ]; cout < < ' n No Results Found for ' < < prefix < < ' n ' ; } } // Insert all the Contacts into the Trie void insertIntoTrie ( string contacts [] int n ) { // Initialize root Node root = new TrieNode (); // Insert each contact into the trie for ( int i = 0 ; i < n ; i ++ ) insert ( contacts [ i ]); } // Driver program to test above functions int main () { // Contact list of the User string contacts [] = { 'gforgeeks' 'geeksquiz' }; // Size of the Contact List int n = sizeof ( contacts ) / sizeof ( string ); // Insert all the Contacts into Trie insertIntoTrie ( contacts n ); string query = 'gekk' ; // Note that the user will enter 'g' then 'e' so // first display all the strings with prefix as 'g' // and then all the strings with prefix as 'ge' displayContacts ( query ); return 0 ; }
Java // Java Program to Implement a Phone // Directory Using Trie Data Structure import java.util.* ; class TrieNode { // Each Trie Node contains a Map 'child' // where each alphabet points to a Trie // Node. HashMap < Character TrieNode > child ; // 'isLast' is true if the node represents // end of a contact boolean isLast ; // Default Constructor public TrieNode () { child = new HashMap < Character TrieNode > (); // Initialize all the Trie nodes with NULL for ( char i = 'a' ; i <= 'z' ; i ++ ) child . put ( i null ); isLast = false ; } } class Trie { TrieNode root ; // Insert all the Contacts into the Trie public void insertIntoTrie ( String contacts [] ) { root = new TrieNode (); int n = contacts . length ; for ( int i = 0 ; i < n ; i ++ ) { insert ( contacts [ i ] ); } } // Insert a Contact into the Trie public void insert ( String s ) { int len = s . length (); // 'itr' is used to iterate the Trie Nodes TrieNode itr = root ; for ( int i = 0 ; i < len ; i ++ ) { // Check if the s[i] is already present in // Trie TrieNode nextNode = itr . child . get ( s . charAt ( i )); if ( nextNode == null ) { // If not found then create a new TrieNode nextNode = new TrieNode (); // Insert into the HashMap itr . child . put ( s . charAt ( i ) nextNode ); } // Move the iterator('itr') to point to next // Trie Node itr = nextNode ; // If its the last character of the string 's' // then mark 'isLast' as true if ( i == len - 1 ) itr . isLast = true ; } } // This function simply displays all dictionary words // going through current node. String 'prefix' // represents string corresponding to the path from // root to curNode. public void displayContactsUtil ( TrieNode curNode String prefix ) { // Check if the string 'prefix' ends at this Node // If yes then display the string found so far if ( curNode . isLast ) System . out . println ( prefix ); // Find all the adjacent Nodes to the current // Node and then call the function recursively // This is similar to performing DFS on a graph for ( char i = 'a' ; i <= 'z' ; i ++ ) { TrieNode nextNode = curNode . child . get ( i ); if ( nextNode != null ) { displayContactsUtil ( nextNode prefix + i ); } } } // Display suggestions after every character enter by // the user for a given string 'str' void displayContacts ( String str ) { TrieNode prevNode = root ; // 'flag' denotes whether the string entered // so far is present in the Contact List String prefix = '' ; int len = str . length (); // Display the contact List for string formed // after entering every character int i ; for ( i = 0 ; i < len ; i ++ ) { // 'str' stores the string entered so far prefix += str . charAt ( i ); // Get the last character entered char lastChar = prefix . charAt ( i ); // Find the Node corresponding to the last // character of 'str' which is pointed by // prevNode of the Trie TrieNode curNode = prevNode . child . get ( lastChar ); // If nothing found then break the loop as // no more prefixes are going to be present. if ( curNode == null ) { System . out . println ( 'nNo Results Found for ' + prefix ); i ++ ; break ; } // If present in trie then display all // the contacts with given prefix. System . out . println ( 'nSuggestions based on ' + prefix + ' are ' ); displayContactsUtil ( curNode prefix ); // Change prevNode for next prefix prevNode = curNode ; } for ( ; i < len ; i ++ ) { prefix += str . charAt ( i ); System . out . println ( 'nNo Results Found for ' + prefix ); } } } // Driver code class Main { public static void main ( String args [] ) { Trie trie = new Trie (); String contacts [] = { 'gforgeeks' 'geeksquiz' }; trie . insertIntoTrie ( contacts ); String query = 'gekk' ; // Note that the user will enter 'g' then 'e' so // first display all the strings with prefix as 'g' // and then all the strings with prefix as 'ge' trie . displayContacts ( query ); } }
Python3 # Python Program to Implement a Phone # Directory Using Trie Data Structure class TrieNode : def __init__ ( self ): # Each Trie Node contains a Map 'child' # where each alphabet points to a Trie # Node. self . child = {} self . is_last = False # Making root NULL for ease so that it doesn't # have to be passed to all functions. root = TrieNode () # Insert a Contact into the Trie def insert ( string ): # 'itr' is used to iterate the Trie Nodes itr = root for char in string : # Check if the s[i] is already present in # Trie if char not in itr . child : # If not found then create a new TrieNode itr . child [ char ] = TrieNode () # Move the iterator('itr') to point to next # Trie Node itr = itr . child [ char ] # If its the last character of the string 's' # then mark 'isLast' as true itr . is_last = True # This function simply displays all dictionary words # going through current node. String 'prefix' # represents string corresponding to the path from # root to curNode. def display_contacts_util ( cur_node prefix ): # Check if the string 'prefix' ends at this Node # If yes then display the string found so far if cur_node . is_last : print ( prefix ) # Find all the adjacent Nodes to the current # Node and then call the function recursively # This is similar to performing DFS on a graph for i in range ( ord ( 'a' ) ord ( 'z' ) + 1 ): char = chr ( i ) next_node = cur_node . child . get ( char ) if next_node : display_contacts_util ( next_node prefix + char ) # Display suggestions after every character enter by # the user for a given query string 'str' def displayContacts ( string ): prev_node = root prefix = '' # Display the contact List for string formed # after entering every character for i char in enumerate ( string ): # 'prefix' stores the string formed so far prefix += char # Find the Node corresponding to the last # character of 'prefix' which is pointed by # prevNode of the Trie cur_node = prev_node . child . get ( char ) # If nothing found then break the loop as # no more prefixes are going to be present. if not cur_node : print ( f 'No Results Found for { prefix } n ' ) break # If present in trie then display all # the contacts with given prefix. print ( f 'Suggestions based on { prefix } are ' end = ' ' ) display_contacts_util ( cur_node prefix ) print () # Change prevNode for next prefix prev_node = cur_node # Once search fails for a prefix we print # 'Not Results Found' for all remaining # characters of current query string 'str'. for char in string [ i + 1 :]: prefix += char print ( f 'No Results Found for { prefix } n ' ) # Insert all the Contacts into the Trie def insertIntoTrie ( contacts ): # Insert each contact into the trie for contact in contacts : insert ( contact ) # Driver program to test above functions # Contact list of the User contacts = [ 'gforgeeks' 'geeksquiz' ] # Size of the Contact List n = len ( contacts ) # Insert all the Contacts into Trie insertIntoTrie ( contacts ) query = 'gekk' # Note that the user will enter 'g' then 'e' so # first display all the strings with prefix as 'g' # and then all the strings with prefix as 'ge' displayContacts ( query ) # This code is contributed by Aman Kumar
C# // C# Program to Implement a Phone // Directory Using Trie Data Structure using System ; using System.Collections.Generic ; class TrieNode { // Each Trie Node contains a Map 'child' // where each alphabet points to a Trie // Node. public Dictionary < char TrieNode > child ; // 'isLast' is true if the node represents // end of a contact public bool isLast ; // Default Constructor public TrieNode () { child = new Dictionary < char TrieNode > (); // Initialize all the Trie nodes with NULL for ( char i = 'a' ; i <= 'z' ; i ++ ) child . Add ( i null ); isLast = false ; } } class Trie { public TrieNode root ; // Insert all the Contacts into the Trie public void insertIntoTrie ( String [] contacts ) { root = new TrieNode (); int n = contacts . Length ; for ( int i = 0 ; i < n ; i ++ ) { insert ( contacts [ i ]); } } // Insert a Contact into the Trie public void insert ( String s ) { int len = s . Length ; // 'itr' is used to iterate the Trie Nodes TrieNode itr = root ; for ( int i = 0 ; i < len ; i ++ ) { // Check if the s[i] is already present in // Trie TrieNode nextNode = itr . child [ s [ i ]]; if ( nextNode == null ) { // If not found then create a new TrieNode nextNode = new TrieNode (); // Insert into the Dictionary if ( itr . child . ContainsKey ( s [ i ])) itr . child [ s [ i ]] = nextNode ; else itr . child . Add ( s [ i ] nextNode ); } // Move the iterator('itr') to point to next // Trie Node itr = nextNode ; // If its the last character of the string 's' // then mark 'isLast' as true if ( i == len - 1 ) itr . isLast = true ; } } // This function simply displays all dictionary words // going through current node. String 'prefix' // represents string corresponding to the path from // root to curNode. public void displayContactsUtil ( TrieNode curNode String prefix ) { // Check if the string 'prefix' ends at this Node // If yes then display the string found so far if ( curNode . isLast ) Console . WriteLine ( prefix ); // Find all the adjacent Nodes to the current // Node and then call the function recursively // This is similar to performing DFS on a graph for ( char i = 'a' ; i <= 'z' ; i ++ ) { TrieNode nextNode = curNode . child [ i ]; if ( nextNode != null ) { displayContactsUtil ( nextNode prefix + i ); } } } // Display suggestions after every character enter by // the user for a given string 'str' public void displayContacts ( String str ) { TrieNode prevNode = root ; // 'flag' denotes whether the string entered // so far is present in the Contact List String prefix = '' ; int len = str . Length ; // Display the contact List for string formed // after entering every character int i ; for ( i = 0 ; i < len ; i ++ ) { // 'str' stores the string entered so far prefix += str [ i ]; // Get the last character entered char lastChar = prefix [ i ]; // Find the Node corresponding to the last // character of 'str' which is pointed by // prevNode of the Trie TrieNode curNode = prevNode . child [ lastChar ]; // If nothing found then break the loop as // no more prefixes are going to be present. if ( curNode == null ) { Console . WriteLine ( 'nNo Results Found for ' + prefix ); i ++ ; break ; } // If present in trie then display all // the contacts with given prefix. Console . WriteLine ( 'nSuggestions based on ' + prefix + ' are ' ); displayContactsUtil ( curNode prefix ); // Change prevNode for next prefix prevNode = curNode ; } for ( ; i < len ; i ++ ) { prefix += str [ i ]; Console . WriteLine ( 'nNo Results Found for ' + prefix ); } } } // Driver code public class GFG { public static void Main ( String [] args ) { Trie trie = new Trie (); String [] contacts = { 'gforgeeks' 'geeksquiz' }; trie . insertIntoTrie ( contacts ); String query = 'gekk' ; // Note that the user will enter 'g' then 'e' so // first display all the strings with prefix as 'g' // and then all the strings with prefix as 'ge' trie . displayContacts ( query ); } } // This code is contributed by PrinciRaj1992
JavaScript < script > // Javascript Program to Implement a Phone // Directory Using Trie Data Structure class TrieNode { constructor () { // Each Trie Node contains a Map 'child' // where each alphabet points to a Trie // Node. // We can also use a fixed size array of // size 256. this . child = {}; // 'isLast' is true if the node represents // end of a contact this . isLast = false ; } } // Making root NULL for ease so that it doesn't // have to be passed to all functions. let root = null ; // Insert a Contact into the Trie function insert ( s ) { const len = s . length ; // 'itr' is used to iterate the Trie Nodes let itr = root ; for ( let i = 0 ; i < len ; i ++ ) { // Check if the s[i] is already present in // Trie const char = s [ i ]; let nextNode = itr . child [ char ]; if ( nextNode === undefined ) { // If not found then create a new TrieNode nextNode = new TrieNode (); // Insert into the Map itr . child [ char ] = nextNode ; } // Move the iterator('itr') to point to next // Trie Node itr = nextNode ; // If its the last character of the string 's' // then mark 'isLast' as true if ( i === len - 1 ) { itr . isLast = true ; } } } // This function simply displays all dictionary words // going through current node. String 'prefix' // represents string corresponding to the path from // root to curNode. function displayContactsUtil ( curNode prefix ) { // Check if the string 'prefix' ends at this Node // If yes then display the string found so far if ( curNode . isLast ) { document . write ( prefix + '
' ); } // Find all the adjacent Nodes to the current // Node and then call the function recursively // This is similar to performing DFS on a graph for ( let i = 97 ; i <= 122 ; i ++ ) { const char = String . fromCharCode ( i ); const nextNode = curNode . child [ char ]; if ( nextNode !== undefined ) { displayContactsUtil ( nextNode prefix + char ); } } } // Display suggestions after every character enter by // the user for a given query string 'str' function displayContacts ( str ) { let prevNode = root ; let prefix = '' ; const len = str . length ; // Display the contact List for string formed // after entering every character let i ; for ( i = 0 ; i < len ; i ++ ) { // 'prefix' stores the string formed so far prefix += str [ i ]; // Get the last character entered const lastChar = prefix [ i ]; // Find the Node corresponding to the last // character of 'prefix' which is pointed by // prevNode of the Trie const curNode = prevNode . child [ lastChar ]; // If nothing found then break the loop as // no more prefixes are going to be present. if ( curNode === undefined ) { document . write ( `No Results Found for ${ prefix } ` + '
' ); i ++ ; break ; } // If present in trie then display all // the contacts with given prefix. document . write ( `Suggestions based on ${ prefix } are ` ); displayContactsUtil ( curNode prefix ); document . write ( '
' ); // Change prevNode for next prefix prevNode = curNode ; } document . write ( '
' ); // Once search fails for a prefix we print // 'Not Results Found' for all remaining // characters of current query string 'str'. for (; i < len ; i ++ ) { prefix += str [ i ]; document . write ( 'No Results Found for ' + prefix + '
' ); } } // Insert all the Contacts into the Trie function insertIntoTrie ( contacts ) { // Initialize root Node root = new TrieNode (); const n = contacts . length ; // Insert each contact into the trie for ( let i = 0 ; i < n ; i ++ ) { insert ( contacts [ i ]); } } // Driver program to test above functions // Contact list of the User const contacts = [ 'gforgeeks' 'geeksquiz' ]; //Insert all the Contacts into Trie insertIntoTrie ( contacts ); const query = 'gekk' ; // Note that the user will enter 'g' then 'e' so // first display all the strings with prefix as 'g' // and then all the strings with prefix as 'ge' displayContacts ( query ); // This code is contributed by Utkarsh Kumar. < /script>
산출
Suggestions based on gare geeksquiz gforgeeks Suggestions based on geare geeksquiz No Results Found for gek No Results Found for gekk
시간 복잡도: O(n*m) 여기서 n은 접촉 수이고 m은 접촉 문자열의 최대 길이입니다.
보조 공간: O(n*m)
