93 lines
1.6 KiB
C++
93 lines
1.6 KiB
C++
#include<bits/stdc++.h>
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#include<iostream>
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using namespace std;
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// Basic Structure of a Tree
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struct Node
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{
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int data;
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struct Node *left;
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struct Node *right;
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Node(int val) {
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data = val;
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left = NULL;
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right = NULL;
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}
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};
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//Function which prints out the top view of the tree
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void topView(struct Node * root)
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{
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if (root == NULL)
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return;
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queue<pair<struct Node*, int>>q;
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map<int, int> mp;
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int d;
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q.push({root, 0});
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Node *temp = NULL;
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while (!q.empty())
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{
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temp = q.front().first;
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d = q.front().second;
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if (mp.find(d) == mp.end())
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{
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//cout << temp->data <<" ";
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mp[d] = temp->data;
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}
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if (temp->left)
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{
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q.push({temp->left, d - 1}); //every node left to its predecessor is tagged a number less than one
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}
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if (temp->right)
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{
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q.push({temp->right, d + 1}); //every node right to its predecessor is tagged a number greater than one
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}
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q.pop();
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}
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for (auto i = mp.begin(); i != mp.end(); i++)
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cout << i->second << " ";
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}
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int main()
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{
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Node* root = new Node(1);
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root->left = new Node(2);
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root->right = new Node(3);
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root->left->left = new Node(4);
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root->left->right = new Node(5);
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root->right->right = new Node(7);
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/*
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1
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/ \
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2 3
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/ \ \
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4 5 7
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Expected-> 4 2 1 3 7
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*/
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cout << "The top view of the tree is : " << endl;
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topView(root);
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return 0;
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} |