Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Articles on Trending Technologies
Technical articles with clear explanations and examples
Find the value of ln(N!) using Recursion using C++.
Suppose we have a number N, our task is to find ln(N!) using recursion. ln() is basically log base e. To solve this we can use this formula −$$\ln\lgroup N!\rgroup=\ln\lgroup N*\lgroup N-1\rgroup *\lgroup N-2\rgroup *\dotsm*2*1\rgroup=\ln\lgroup N\rgroup+\ln\lgroup N+1\rgroup+\dotsm+\ln\lgroup 1\rgroup$$Example#include #include using namespace std; double factLog(int n) { if (n
Read MorePerl Sequential Number Arrays
Perl offers a shortcut for sequential numbers and letters. Rather than typing out each element when counting to 100 for example, we can do something like as follows −Example#!/usr/bin/perl @var_10 = (1..10); @var_20 = (10..20); @var_abc = (a..z); print "@var_10"; # Prints number from 1 to 10 print "@var_20"; # Prints number from 10 to 20 print "@var_abc"; # Prints number from a to zHere double dot (..) is called range operator. This will produce the following result −1 2 3 4 5 6 7 8 9 10 10 11 12 13 14 15 16 17 18 19 20 a b c d e f g h i j k l m n o p q r s t u v w x y z
Read MoreFind the sum of digits of a number at even and odd places in C++
Suppose, we have an integer N, We have to find the sum of the odd place digits and the even place digits. So if the number is like 153654, then odd_sum = 9, and even_sum = 15.To solve this, we can extract all digits from last digit, if the original number has odd number of digits, then the last digit must be odd positioned, else it will be even positioned. After process a digit, we can invert the state from odd to even and vice versa.Example#include using namespace std; bool isOdd(int x){ if(x % 2 == 0) return ...
Read MoreArray Size in Perl
The size of an array in Perl can be determined using the scalar context on the array - the returned value will be the number of elements in the array −@array = (1, 2, 3); print "Size: ", scalar @array, "";The value returned will always be the physical size of the array, not the number of valid elements. You can demonstrate this, and the difference between scalar @array and $#array, using this fragment is as follows −Example#!/usr/bin/perl @array = (1, 2, 3); $array[50] = 4; $size = @array; $max_index = $#array; print "Size: $size"; print "Max Index: $max_index";OutputThis will ...
Read MoreFind element in a sorted array whose frequency is greater than or equal to n/2 in C++.
Consider we have an array with size n. This array is sorted. There is one element whose frequency is greater than or equal to n/2, where n is the number of elements in the array. So if the array is like [3, 4, 5, 5, 5], then the output will be 5.If we closely observe these type of array, we can easily notice that the number whose frequency is greater than or equal to n/2, will be present at index n/2 also. So the element can be found at position n/2ExampleSource Code: #include using namespace std; int higherFreq(int arr[], int ...
Read MoreAdding and Removing Elements in Perl Array
Perl provides a number of useful functions to add and remove elements in an array. You may have a question what is a function? So far you have used the print function to print various values. Similarly, there are various other functions or sometimes called subroutines, which can be used for various other functionalities.Sr.No.Types & Description1push @ARRAY, LISTPushes the values of the list onto the end of the array.2pop @ARRAYPops off and returns the last value of the array.3shift @ARRAYShifts the first value of the array off and returns it, shortening the array by 1 and moving everything down.4unshift @ARRAY, ...
Read MoreSlicing Array Elements in Perl
You can also extract a "slice" from an array - that is, you can select more than one item from an array in order to produce another array.Example#!/usr/bin/perl @days = qw/Mon Tue Wed Thu Fri Sat Sun/; @weekdays = @days[3, 4, 5]; print "@weekdays";OutputThis will produce the following result −Thu Fri SatThe specification for a slice must have a list of valid indices, either positive or negative, each separated by a comma. For speed, you can also use the .. range operator −Example#!/usr/bin/perl @days = qw/Mon Tue Wed Thu Fri Sat Sun/; @weekdays = @days[3..5]; print "@weekdays";OutputThis will produce the ...
Read MoreFind four elements a, b, c and d in an array such that a+b = c+d in C++
Suppose we have a list of integers. Our task is to find four distinct integers as two pairs like (a, b) and (c, d), such that a+b = c+d. If there are multiple answers, then print only one. Suppose the array elements are like: A = [7, 5, 9, 3, 6, 4, 2], then pairs can be (7, 3) and (6, 4)Here we will use the hashing technique. We use the sum as key as pair as the value in the hash table. We have to follow these steps to solve this problem.For i in range 0 to n – ...
Read MoreFind frequency of each element in a limited range array in less than O(n) time in C++
Suppose we have an array of integers. The array is A, and the size is n. Our task is to find the frequency of all elements in the array less than O(n) time. The size of the elements must be less than one value say M. Here we will use the binary search approach. Here we will recursively divide the array into two parts if the end elements are different, if both its end elements are the same, it means all elements in the array are the same as the array is already sorted.Example#include #include using namespace std; void calculateFreq(int ...
Read MoreFind gcd(a^n, c) where a, n and c can vary from 1 to 10^9 in C++
We have to find the GCD of two numbers of which one number can be as big as (109 ^ 109), which cannot be stored in some data types like long or any other. So if the numbers are a = 10248585, n = 1000000, b = 12564, then result of GCD(a^n, b) will be 9.As the numbers are very long, we cannot use the Euclidean algorithm. We have to use the modular exponentiation with O(log n) complexity.Example#include #include using namespace std; long long power(long long a, long long n, long long b) { long long res = 1; ...
Read More