Create Sum_of_leaf_nodes_at_each_horizontal_level_in_a_binary_tree.cpp

C++/Sum_of_leaf_nodes_at_each_horizontal_level_in_a_binary_tree.cpp

@@ -0,0 +1,88 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+// Tree node structure
+class Node {
+public:
+    int data;
+    Node *left, *right;
+
+    Node(int data)
+    {
+        this->data = data;
+        left = right = NULL;
+    }
+};
+
+// Function to print the sum of leaf nodes
+// at each horizontal level
+void printLevelSum(Node* root)
+{
+    if (root == NULL) {
+        cout << "No nodes present\n";
+        return;
+    }
+
+    // Map to hold sum at each level
+    map<int, int> mp;
+
+    // Queue to hold tree node with level
+    queue<pair<Node*, int> > q;
+
+    // Root node is at level 1
+    q.push({ root, 1 });
+
+    pair<Node*, int> p;
+
+    // Level Order Traversal of tree
+    while (!q.empty()) {
+        p = q.front();
+        q.pop();
+
+        // Create a key for each level
+        // in the map
+        if (mp.find(p.second) == mp.end()) {
+            mp[p.second] = 0;
+        }
+
+        // If current node is a leaf node
+        if (p.first->left == NULL
+            && p.first->right == NULL) {
+
+            // Adding value in the map
+            // corresponding to its level
+            mp[p.second] += p.first->data;
+        }
+
+        if (p.first->left)
+            q.push({ p.first->left, p.second + 1 });
+        if (p.first->right)
+            q.push({ p.first->right, p.second + 1 });
+    }
+
+    // Print the sum at each level
+    for (auto i : mp) {
+        cout << i.second << endl;
+    }
+}
+
+// Driver Code
+int main()
+{
+    Node* root = new Node(1);
+    root->left = new Node(2);
+    root->right = new Node(3);
+    root->left->left = new Node(4);
+    root->left->right = new Node(5);
+    root->right->left = new Node(6);
+    root->right->right = new Node(7);
+    root->left->left->right = new Node(8);
+    root->left->right->right = new Node(9);
+    root->right->right->left = new Node(10);
+    root->right->right->right = new Node(11);
+    root->left->left->right->right = new Node(12);
+
+    printLevelSum(root);
+
+    return 0;
+}