A pentagonal pyramidal number is equal to the number of items in a pentagonal base pyramid. Look at some Pentagonal numbers below.Sum of Pentagonal Numbers till N equals to Nth Pentagonal Pyramidal Number. In this article, we will discuss finding the Nth Pentagonal Pyramidal number, for exampleInput : N = 4 Output : 40 Explanation : Sum of first four pentagonal numbers 1, 5, 12, 22 is 40. Input : N = 6 Output : 126 Explanation : Sum of first four pentagonal numbers 1, 5, 12, 22, 35, 51 is 40.Approach to find The SolutionSimple ApproachAs per the ... Read More

In the given problem, we are given an integer n we need to find Pn, i.e., the pell number in that position. Now, as we know, pell number is a part of a series given by this formula −Pn = 2*Pn-1 + Pn-2With first two starting numbers − P0 = 0 and P1 = 1Approach to find The SolutionNow we will solve this problem by two approaches: recursive and iterative.Recursive ApproachIn this formula, we will recursively apply the formula of Pell Number and do n iterations.Example#include using namespace std; int pell(int n) {    if(n

In this article we are given values of several rows and several columns. We need to print a Box pattern such that 1’s get printed on 1st row, 1st column, last row, last column, and 0’s get printed on remaining elements. For example −Input : rows = 5, columns = 4 Output :    1 1 1 1    1 0 0 1    1 0 0 1    1 0 0 1    1 1 1 1 Input : rows = 8, columns = 9 Output :    1 1 1 1 1 1 1 1 1   ... Read More

Given a binary search tree, and we are required to reverse its path from a particular key, for example.Approach to Find the SolutionIn this approach, we will make a queue and push all the nodes until we get the root.Example  #include using namespace std; struct node {    int key;    struct node *left, *right; }; struct node* newNode(int item){    struct node* temp = new node;    temp->key = item;    temp->left = temp->right = NULL;    return temp; } void inorder(struct node* root){    if (root != NULL) {        inorder(root->left);        cout ... Read More

Discuss a problem based on expanding the matrix. Expanding matrix is a matrix whose size continuously increases by some factor.Here we have a matrix of characters whose size is expanding by a factor of 2, i.e., if the original size of the matrix is N * N, then the size of the expanded matrix becomes 2N * 2N. We are given a sequence of characters present at ( i, j ), and we need to return the sequence of characters present at (i, (j - N - 1)%N).Let’s understand by visualizing some initial expanded matrix, Given Matrix -> [ a, ... Read More

Discuss dividing an unsigned integer using a division algorithm. Some division algorithms are applied on paper, and others are implemented on digital circuits. Division algorithms are of two types: slow division algorithm and fast division algorithm. Slow division algorithm includes restoring, non-performing restoring, SRT, and non-restoring algorithm.In this tutorial, we will discuss the Restoring algorithm, assuming that 0 < divisor < dividend.Approach to Find the SolutionIn this, we will use register Q to store quotient, register A to store remainder, and M to store divisor. The initial value of A is kept at 0, and its value is restored, which ... Read More

In this article, we have an array containing distinct elements. We need to print the pairs of positive-negative values in the array with the same absolute value and print them in sorted order for examples −Input : arr[] = { 1, -1, 11, 12, 56, 77, -56, -12, -88} Output : -1 1 -12 12 -56 56 Input : arr[] = {30, 40, 50, 77, -51, -50, -40} Output : -40 40 -50 50Approach to find The SolutionThe first approach that comes to our mind is the Brute Force approach, and we make up another one called the Efficient ... Read More

In this article, we will discuss finding a pair with a maximum sum in a given matrix or 2-D array. For exampleInput : matrix[m][n] = {    { 3, 5, 2 },    { 2, 6, 47 },    { 1, 64, 66 } } Output : 130 Explanation : maximum sum is 130 from element pair 64 and 66. Input : matrix[m][n] = {    { 55, 22, 46 },    { 6, 2, 1 },    { 3, 24, 52 } } Output : 107 Explanation : maximum sum is 130 from element pair 55 and ... Read More

In this article, we will discuss the program of finding a pair with a given sum in a given matrix. For example −Input : matrix[n][m] = {    { 4, 6, 4, 65 },    { 56, 1, 12, 32 },    { 4, 5, 6, 44 },    { 13, 9, 11, 25 } }, SUM = 20 Output : Pair exists. Explanation : Sum = 20 is equal to the sum of numbers 9 and 11 which exists in the matrix. Input : matrix[n][m] = {    { 5, 7, 3, 45 ... Read More

Discuss the problem of representing a number in the power of another number. We are given two numbers, x, and y. We need to tell whether y can be represented in the power of x where each power of x can be used once, for exampleInput: x = 4, y = 11 Output: true Explanation: 4^2 - 4^1 - 4^0 = 11 Hence y can be represented in the power of x. Input: x = 2, y = 19 Output: true Explanation: 2^4 + 2^1 + 2^0 =19 Hence y can be represented in the power of x. ... Read More