Profunditat d'un arbre N-ari
Donat un arbre n-ari que conté valors de nodes positius, la tasca és trobar el profunditat de l'arbre.
Nota: An arbre n-ari és un arbre on pot tenir cada node zero o més nodes fills. A diferència d'un arbre binari que té com a màxim dos fills per node (esquerra i dreta) l'arbre n-ari permet múltiples branques o fills per a cada node.
Exemples:
Entrada:
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Sortida: 3
Explicació: El camí més llarg des de l'arrel (node 81) fins a una fulla és 81 -> 26 -> 95 o 81 -> 26 -> 86 amb una profunditat màxima de 3.Entrada:
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Sortida: 2
Explicació: El camí més llarg des de l'arrel (node 4) fins a qualsevol fulla (nodes 5 o 7) és 2, ja que només requereix dos nivells de recorregut.
Enfocament:
La idea és calcular el profunditat d'un arbre N-ari recursivament inicialitzar el profunditat màxima com a 0, calculeu recursivament el profunditat per a cada nen i fer-ne un seguiment profunditat més alta trobada. Finalment afegir 1 a la profunditat màxima (per al node actual) i retornar el resultat . Aquest enfocament garanteix que trobem el camí més llarg des de l'arrel fins a qualsevol node full.
L'arbre N-Ary es pot travessar igual que un arbre normal. Només hem de considerar tots els fills d'un node donat i cridar recursivament aquesta funció a cada node.
C++ // C++ Code to find the depth of an N-ary tree #include using namespace std ; class Node { public : int data ; vector < Node *> children ; Node ( int val ) { data = val ; } }; // Recursive function to calculate maximum depth int maxDepth ( Node * root ) { // If the node is null depth is 0 if ( ! root ) { return 0 ; } int depth = 0 ; // Recur for all children and find the maximum depth for ( auto child : root -> children ) { depth = max ( depth maxDepth ( child )); } // Add 1 to include the current node // in the depth count return depth + 1 ; } int main () { // Representation of given N-ary tree // 1 // / | // 2 3 4 // / // 5 6 Node * root = new Node ( 1 ); root -> children . push_back ( new Node ( 2 )); root -> children . push_back ( new Node ( 3 )); root -> children . push_back ( new Node ( 4 )); root -> children [ 0 ] -> children . push_back ( new Node ( 5 )); root -> children [ 2 ] -> children . push_back ( new Node ( 6 )); cout < < maxDepth ( root ); return 0 ; }
Java // Java Code to find the depth of an N-ary tree import java.util.* ; class Node { int data ; List < Node > children ; Node ( int val ) { data = val ; children = new ArrayList <> (); } } // Recursive function to calculate // maximum depth class GfG { static int maxDepth ( Node root ) { // If the node is null depth is 0 if ( root == null ) { return 0 ; } int depth = 0 ; // Recur for all children and find // the maximum depth for ( Node child : root . children ) { depth = Math . max ( depth maxDepth ( child )); } // Add 1 to include the current node // in the depth count return depth + 1 ; } public static void main ( String [] args ) { // Representation of given N-ary tree // 1 // / | // 2 3 4 // / // 5 6 Node root = new Node ( 1 ); root . children . add ( new Node ( 2 )); root . children . add ( new Node ( 3 )); root . children . add ( new Node ( 4 )); root . children . get ( 0 ). children . add ( new Node ( 5 )); root . children . get ( 2 ). children . add ( new Node ( 6 )); System . out . println ( maxDepth ( root )); } }
Python # Python Code to find the depth # of an N-ary tree class Node : def __init__ ( self val ): self . data = val self . children = [] # Recursive function to calculate # maximum depth def max_depth ( root ): # If the node is None depth is 0 if not root : return 0 depth = 0 # Recur for all children and # find the maximum depth for child in root . children : depth = max ( depth max_depth ( child )) # Add 1 to include the current # node in the depth count return depth + 1 if __name__ == '__main__' : # Representation of given N-ary tree # 1 # / | # 2 3 4 # / # 5 6 root = Node ( 1 ) root . children . append ( Node ( 2 )) root . children . append ( Node ( 3 )) root . children . append ( Node ( 4 )) root . children [ 0 ] . children . append ( Node ( 5 )) root . children [ 2 ] . children . append ( Node ( 6 )) print ( max_depth ( root ))
C# // C# Code to find the depth of an N-ary tree using System ; using System.Collections.Generic ; class Node { public int data ; public List < Node > children ; public Node ( int val ) { data = val ; children = new List < Node > (); } } // Recursive function to calculate // maximum depth class GfG { static int MaxDepth ( Node root ) { // If the node is null depth is 0 if ( root == null ) { return 0 ; } int depth = 0 ; // Recur for all children and find the maximum depth foreach ( Node child in root . children ) { depth = Math . Max ( depth MaxDepth ( child )); } // Add 1 to include the current // node in the depth count return depth + 1 ; } static void Main ( string [] args ) { // Representation of given N-ary tree // 1 // / | // 2 3 4 // / // 5 6 Node root = new Node ( 1 ); root . children . Add ( new Node ( 2 )); root . children . Add ( new Node ( 3 )); root . children . Add ( new Node ( 4 )); root . children [ 0 ]. children . Add ( new Node ( 5 )); root . children [ 2 ]. children . Add ( new Node ( 6 )); Console . WriteLine ( MaxDepth ( root )); } }
JavaScript // JavaScript Code to find the depth // of an N-ary tree class Node { constructor ( val ) { this . data = val ; this . children = []; } } // Recursive function to calculate // maximum depth function maxDepth ( root ) { // If the node is null depth is 0 if ( ! root ) { return 0 ; } let depth = 0 ; // Recur for all children and find // the maximum depth for ( let child of root . children ) { depth = Math . max ( depth maxDepth ( child )); } // Add 1 to include the current node // in the depth count return depth + 1 ; } // Representation of given N-ary tree // 1 // / | // 2 3 4 // / // 5 6 const root = new Node ( 1 ); root . children . push ( new Node ( 2 )); root . children . push ( new Node ( 3 )); root . children . push ( new Node ( 4 )); root . children [ 0 ]. children . push ( new Node ( 5 )); root . children [ 2 ]. children . push ( new Node ( 6 )); console . log ( maxDepth ( root ));
Sortida
3
Complexitat temporal: O(n) ja que cada node es visita una vegada, on n és el nombre total de nodes de l'arbre N-ari.
Espai auxiliar: O(h) on h és l'alçada de l'arbre a causa de l'ús recursiu de la pila de trucades.