CODEWITHSUNDEEP
c++11treestack
Anonymous
Anonymous

Reputation: 83

60:6: error: no matching member function for call to 'push' s.push(head);

The compiler is saying that there is no matching function for stack::push() or any stack function I have used in the below code.

This code is for an iterative pre-order traversal of a tree.

Here is the code (or PasteBin):

#include <iostream>
#include <stack>

struct Node {
    int data;
    Node *parent, *left, *right;
} *root = nullptr;

Node *createNode(int num) {
    Node *new_node = new Node;
    new_node -> data = num;
    new_node -> parent = new_node -> left =  new_node -> right = nullptr;

    return new_node;
}

void createTree(int num) {
    Node *new_node = createNode(num);

    if(!root) {
        root = new_node;
        return;
    }
    Node *head = root, *parent_node = root;
    while(head) {
        if(num < head -> data) {
            if(head -> left == nullptr) {
                head -> left = new_node;
                new_node -> parent = parent_node;
            }
            parent_node = head;
            head = head -> left;
        }
        else {
            if(head -> right == nullptr) {
                head -> right = new_node;
                new_node -> parent = parent_node;
            }
            parent_node = head;
            head = head -> right;
        }
    }
}

void preorderTraversal(Node *head) {
    std::stack<Node> s;

    while(1) {
        while(head) {
            s.push(head);
            std::cout << head -> data << " ";
            head = head -> left;
       }

        if(!s.empty())
            break;

        head = s.top();
        head = head -> right;
        s.pop();
    }
}

int main() {
    int num;
    for(int i = 0; i < 7; i++) {
        std::cin >> num;
        createTree(num);
    }

    preorderTraversal(root);
    std::cout << std::endl;
    return 0;
}

Upvotes: 2

Views: 5000

Answers (1)

Anonymous
Anonymous

Reputation: 83

It should be std::stack<Node*> s in place of std::stack<Node> s because the stack should contain elements which are pointer to the Node or Node*.

Sorry, my bad!

Upvotes: 3

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