From 6675545bdb58748e21e2baabfa2c5abef046b353 Mon Sep 17 00:00:00 2001
From: sri-samurai28 <sriansuchou137@gmail.com>
Date: Sat, 3 Oct 2020 00:55:12 +0530
Subject: [PATCH 1/2] added common tree traversal methods i.e inorder ,
 preorder , postorder , levelorder

---
 README.md                                    |   5 +
 Trees_Algo/common_tree_traversal_methods.cpp | 111 +++++++++++++++++++
 2 files changed, 116 insertions(+)
 create mode 100755 Trees_Algo/common_tree_traversal_methods.cpp

diff --git a/README.md b/README.md
index 39cb373..22f2fc5 100644
--- a/README.md
+++ b/README.md
@@ -34,3 +34,8 @@ The purpose of this repository is to get all the Algorithms required for Competi
 1)Spiral search in 2d array
 
   
+## Trees_Algo
+1) LCA.cpp
+2) Topview.cpp
+3) Bottomview.cpp
+4) Common_tree_traversal.cpp
\ No newline at end of file
diff --git a/Trees_Algo/common_tree_traversal_methods.cpp b/Trees_Algo/common_tree_traversal_methods.cpp
new file mode 100755
index 0000000..05b2cfa
--- /dev/null
+++ b/Trees_Algo/common_tree_traversal_methods.cpp
@@ -0,0 +1,111 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <iostream>
+#include <bits/stdc++.h>
+#include <climits>
+using namespace std;
+
+struct node
+{
+    int data;
+    struct node *left;
+    struct node *right;
+};
+
+struct node *newnode(int data)
+{
+    struct node *p = new (struct node);
+    //struct node* p = (struct node*)malloc(sizeof(struct node));
+
+    p->data = data;
+    p->left = NULL;
+    p->right = NULL;
+    return p;
+}
+
+//Inorder (Left, Root, Right)
+//Preorder (Root, Left, Right)
+//Postorder (Left, Right, Root)
+//Levelorder
+int height(node *root)
+{
+    // Write your code here.
+    if (root == NULL)
+    {
+        return 0;
+    }
+    if (root->left == NULL && root->right == NULL)
+    {
+        return 0;
+    }
+    return std::max(height(root->left) + 1, height(root->right) + 1);
+}
+
+int printlevel(struct node *root, int level)
+{
+    if (root == NULL)
+        return 0;
+    if (level == 0)
+        cout << root->data << " ";
+    else
+    {
+        printlevel(root->left, level - 1);
+        printlevel(root->right, level - 1);
+    }
+}
+
+void levelOrder(struct node *root)
+
+{
+    int h = height(root);
+    for (int i = 0; i <= h; i++)
+    {
+        printlevel(root, i);
+    }
+}
+
+int preorder(struct node *root)
+{
+    if (root == NULL)
+        return 0;
+    cout << root->data << " ";
+    preorder(root->left);
+    preorder(root->right);
+}
+
+int inorder(struct node *root)
+{
+    if (root == NULL)
+        return 0;
+    inorder(root->left);
+    cout << root->data << " ";
+    inorder(root->right);
+}
+int postorder(struct node *root)
+{
+    if (root == NULL)
+        return 0;
+    postorder(root->left);
+    postorder(root->right);
+    cout << root->data << " ";
+}
+
+int main()
+{
+    struct node *root = newnode(3);
+    root->left = newnode(7);
+    root->right = newnode(5);
+    root->right->right = newnode(11);
+    root->left->left = newnode(9);
+
+    printf("\nTree traversed in preorder=\n");
+    preorder(root);
+    printf("\nTree traversed in inorder=\n");
+    inorder(root);
+    printf("\nTree traversed in postorder=\n");
+    postorder(root);
+    printf("\nTree traversed in levelorder=\n");
+    levelOrder(root);
+
+    return 0;
+}

From 7737c17191ab5b8b863675fe8737582d80c29696 Mon Sep 17 00:00:00 2001
From: sri-samurai28 <sriansuchou137@gmail.com>
Date: Sat, 3 Oct 2020 01:10:44 +0530
Subject: [PATCH 2/2] =?UTF-8?q?//Computes=20the=20last=20digit=20of=20=20F?=
 =?UTF-8?q?ibonacci=20series=20square=20sum-=20F0^2=20+=20F1^2=20+=20?=
 =?UTF-8?q?=C2=B7=20=C2=B7=20=C2=B7=20+=20Fn^2=20in=20constant=20time.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Mathematics_Algo/fibonacci_sum_squares.cpp | 32 ++++++++++++++++++++++
 README.md                                  |  1 +
 2 files changed, 33 insertions(+)
 create mode 100755 Mathematics_Algo/fibonacci_sum_squares.cpp

diff --git a/Mathematics_Algo/fibonacci_sum_squares.cpp b/Mathematics_Algo/fibonacci_sum_squares.cpp
new file mode 100755
index 0000000..2e4e67e
--- /dev/null
+++ b/Mathematics_Algo/fibonacci_sum_squares.cpp
@@ -0,0 +1,32 @@
+#include <iostream>
+
+//Computes the last digit of  Fibonacci series square sum- F0^2 + F1^2 + · · · + Fn^2 in constant time.
+long long fibonacci_fast(int n)
+{
+
+    long long f[n];
+    f[0] = 0;
+    f[1] = 1;
+
+    for (int i = 2; i <= n; i++)
+    {
+        f[i] = (f[i - 1] + f[i - 2]) % 10;
+    }
+
+    return f[n];
+}
+long long fib_square(long long n)
+{
+    if (n < 1)
+        return 0;
+    long long x = fibonacci_fast(n % 60);
+    long long y = fibonacci_fast((n + 1) % 60);
+    long long z = (x * y) % 10;
+    return z;
+}
+int main()
+{
+    long long n = 0;
+    std::cin >> n;
+    std::cout << fib_square(n);
+}
diff --git a/README.md b/README.md
index 22f2fc5..5970627 100644
--- a/README.md
+++ b/README.md
@@ -26,6 +26,7 @@ The purpose of this repository is to get all the Algorithms required for Competi
   13) totient :- Total numbers from 1 to N whose gcd with N is 1.
   14) fibonacciNumber(n) :- Returns the nth Fibonacci Number in constant time.
   15)Spiral Search in 2d array (C++ code)
+  16) Computes the last digit of fibonacci square series F0^2 + F1^2 + · · · + Fn^2 in constant time.
 
 ## String_Algo
   1) isVowel :- Check whether a character is vowel or not.