Найдите сбалансированный узел в связанном списке
Учитывая связанный список, задача состоит в том, чтобы найти сбалансированный узел в связанном списке. Сбалансированный узел - это узел, в котором сумма всех узлов слева равна сумме всех узлов справа, если такой узел не найден, выведите -1 .
Примеры:
Input: 1 -> 2 -> 7 -> 10 -> 1 -> 6 -> 3 -> NULL
Output: 10
Sum of nodes on the left of 10 is 1 + 2 + 7 = 10
And, to the right of 10 is 1 + 6 + 3 = 10Input: 1 -> 5 -> 5 -> 10 -> -3 -> NULL
Output: -1
Подход:
- Сначала найдите общую сумму значений всех узлов.
- Теперь просмотрите связанный список один за другим и во время обхода отслеживайте сумму значений всех предыдущих узлов и найдите сумму оставшегося узла, вычитая текущее значение узла и сумму значений предыдущих узлов из общей суммы.
- Сравните обе суммы, если они равны, то текущий узел является требуемым узлом, иначе выведите -1.
Below is the implementation of the above approach:
C++
// C++ implementation of the approach #include <bits/stdc++.h> using namespace std; // Structure of a node of linked list class Node { public : int data; Node* next; Node( int data) { this ->data = data; this ->next = NULL; } }; // Push the new node to front of // the linked list Node* push(Node* head, int data) { // Return new node as head if // head is empty if (head == NULL) { return new Node(data); } Node* temp = new Node(data); temp->next = head; head = temp; return head; } // Function to find the balanced node int findBalancedNode(Node* head) { int tsum = 0; Node* curr_node = head; // Traverse through all node // to find the total sum while (curr_node != NULL) { tsum += curr_node->data; curr_node = curr_node->next; } // Set current_sum and remaining // sum to zero int current_sum = 0; int remaining_sum = 0; curr_node = head; // Traversing the list to // check balanced node while (curr_node != NULL) { remaining_sum = tsum - (current_sum + curr_node->data); // If sum of the nodes on the left and // the current node is equal to the sum // of the nodes on the right if (current_sum == remaining_sum) { return curr_node->data; } current_sum += curr_node->data; curr_node = curr_node->next; } return -1; } // Driver code int main() { Node* head = NULL; head = push(head, 3); head = push(head, 6); head = push(head, 1); head = push(head, 10); head = push(head, 7); head = push(head, 2); head = push(head, 1); cout << findBalancedNode(head); return 0; } // This code is contributed by divyehrabadiya07 |
Java
// Java implementation of the approach class GFG{ // Structure of a node of linked list static class Node { int data; Node next; Node( int data) { this .data = data; this .next = null ; } } // Push the new node to front of // the linked list static Node push(Node head, int data) { // Return new node as head if // head is empty if (head == null ) { return new Node(data); } Node temp = new Node(data); temp.next = head; head = temp; return head; } // Function to find the balanced node static int findBalancedNode(Node head) { int tsum = 0 ; Node curr_node = head; // Traverse through all node // to find the total sum while (curr_node != null ) { tsum += curr_node.data; curr_node = curr_node.next; } // Set current_sum and remaining // sum to zero int current_sum = 0 ; int remaining_sum = 0 ; curr_node = head; // Traversing the list to // check balanced node while (curr_node != null ) { remaining_sum = tsum - (current_sum + curr_node.data); // If sum of the nodes on the left and // the current node is equal to the sum // of the nodes on the right if (current_sum == remaining_sum) { return curr_node.data; } current_sum += curr_node.data; curr_node = curr_node.next; } return - 1 ; } // Driver code public static void main(String []args) { Node head = null ; head = push(head, 3 ); head = push(head, 6 ); head = push(head, 1 ); head = push(head, 10 ); head = push(head, 7 ); head = push(head, 2 ); head = push(head, 1 ); System.out.println(findBalancedNode(head)); } } // This code is contributed by rutvik_56 |
Python3
# Python3 implementation of the approach import sys import math # Structure of a node of linked list class Node: def __init__( self , data): self . next = None self .data = data # Push the new node to front of the linked list def push(head, data): # Return new node as head if head is empty if not head: return Node(data) temp = Node(data) temp. next = head head = temp return head # Function to find the balanced node def findBalancedNode(head): tsum = 0 curr_node = head # Traverse through all node # to find the total sum while curr_node: tsum + = curr_node.data curr_node = curr_node. next # Set current_sum and remaining sum to zero current_sum, remaining_sum = 0 , 0 curr_node = head # Traversing the list to check balanced node while (curr_node): remaining_sum = tsum - (current_sum + curr_node.data) # If sum of the nodes on the left and the current node # is equal to the sum of the nodes on the right if current_sum = = remaining_sum: return curr_node.data current_sum + = curr_node.data curr_node = curr_node. next return - 1 # Driver code if __name__ = = "__main__" : head = None head = push(head, 3 ) head = push(head, 6 ) head = push(head, 1 ) head = push(head, 10 ) head = push(head, 7 ) head = push(head, 2 ) head = push(head, 1 ) print (findBalancedNode(head)) |
C#
// C# implementation of the approach using System; using System.Collections; using System.Collections.Generic; class GFG { // Structure of a node of linked list class Node { public int data; public Node next; public Node( int data) { this .data = data; this .next = null ; } } // Push the new node to front of // the linked list static Node push(Node head, int data) { // Return new node as head if // head is empty if (head == null ) { return new Node(data); } Node temp = new Node(data); temp.next = head; head = temp; return head; } // Function to find the balanced node static int findBalancedNode(Node head) { int tsum = 0; Node curr_node = head; // Traverse through all node // to find the total sum while (curr_node != null ) { tsum += curr_node.data; curr_node = curr_node.next; } // Set current_sum and remaining // sum to zero int current_sum = 0; int remaining_sum = 0; curr_node = head; // Traversing the list to // check balanced node while (curr_node != null ) { remaining_sum = tsum - (current_sum + curr_node.data); // If sum of the nodes on the left and // the current node is equal to the sum // of the nodes on the right if (current_sum == remaining_sum) { return curr_node.data; } current_sum += curr_node.data; curr_node = curr_node.next; } return -1; } // Driver code public static void Main( string []args) { Node head = null ; head = push(head, 3); head = push(head, 6); head = push(head, 1); head = push(head, 10); head = push(head, 7); head = push(head, 2); head = push(head, 1); Console.Write(findBalancedNode(head)); } } // This code is contributed by pratham76 |
10
Сложность времени: O (n)
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