Merge pull request WaderManasi#1 from utkarshbajpai28/patch-1

Create Ancestor matrix for binary tree

Tree/Ancestor matrix for binary tree

@@ -0,0 +1,92 @@
+// C++ program to construct ancestor matrix for 
+// given tree. 
+#include<bits/stdc++.h> 
+using namespace std; 
+#define MAX 100 
+
+/* A binary tree node */
+struct Node 
+{ 
+    int data; 
+    Node *left, *right; 
+}; 
+
+// Creating a global boolean matrix for simplicity 
+bool mat[MAX][MAX]; 
+
+// anc[] stores all ancestors of current node.  This 
+// function fills ancestors for all nodes. 
+// It also returns size of tree.  Size of tree is 
+// used to print ancestor matrix. 
+int ancestorMatrixRec(Node *root, vector<int> &anc) 
+{ 
+    /* base case */
+    if (root == NULL) return 0;; 
+
+    // Update all ancestors of current node 
+    int data = root->data; 
+    for (int i=0; i<anc.size(); i++) 
+       mat[anc[i]][data] = true; 
+
+    // Push data to list of ancestors 
+    anc.push_back(data); 
+
+    // Traverse left and right subtrees 
+    int l = ancestorMatrixRec(root->left, anc); 
+    int r = ancestorMatrixRec(root->right, anc); 
+
+    // Remove data from list the list of ancestors 
+    // as all descendants of it are processed now. 
+    anc.pop_back(); 
+
+    return l+r+1; 
+} 
+
+// This function mainly calls ancestorMatrixRec() 
+void ancestorMatrix(Node *root) 
+{ 
+    // Create an empty ancestor array 
+    vector<int> anc; 
+
+    // Fill ancestor matrix and find size of 
+    // tree. 
+    int n = ancestorMatrixRec(root, anc); 
+
+    // Print the filled values 
+    for (int i=0; i<n; i++) 
+    { 
+        for (int j=0; j<n; j++) 
+            cout << mat[i][j] << " "; 
+        cout << endl; 
+    } 
+} 
+
+/* Helper function to create a new node */
+Node* newnode(int data) 
+{ 
+    Node* node = new Node; 
+    node->data = data; 
+    node->left = node->right = NULL; 
+    return (node); 
+} 
+
+/* Driver program to test above functions*/
+int main() 
+{ 
+    /* Construct the following binary tree 
+                5 
+              /   \ 
+            1      2 
+          /  \    / 
+         0    4  3    */
+    Node *root        = newnode(5); 
+    root->left        = newnode(1); 
+    root->right       = newnode(2); 
+    root->left->left  = newnode(0); 
+    root->left->right = newnode(4); 
+    root->right->left = newnode(3); 
+
+    ancestorMatrix(root); 
+
+    return 0; 
+}