Sometimes, you may come across a situation, when you want to have a function, which can take variable number of arguments, i.e., parameters, instead of predefined number of parameters. The C/C++ programming language provides a solution for this situation and you are allowed to define a function which can accept variable number of parameters based on your requirement. The following example shows the definition of such a function.int func(int, ... ) { . . . } int main() { func(1, 2, 3); func(1, 2, 3, ... Read More

In this section, we will see how to clear the cin buffer in C++. Before entering into that discussion, let us see what is the buffer in C++.The buffer is a temporary storage area. All standard IO devices uses buffers to hold data while they are working. In C++ also the stream is basically the buffer. When we press some key, that does not send to the program. They are stored into buffers. It is buffered by the operating system till the time is allotted to the program.Sometimes we need to clear the unwanted buffer, so when next input is ... Read More

Heap OverflowHeap is used to store dynamic variables. It is a region of process’s memory. malloc(), calloc(), resize() all these inbuilt functions are generally used to store dynamic variables.Heap overflow occurs when −A) If we allocate dynamic large number of variables −int main() {    float *ptr = (int *)malloc(sizeof(float)*1000000.0)); }B) If we continuously allocate memory and do not free after using it.int main() {    for (int i=0; i

In this section we will see what is the placement new operator in C++. This placement new is another variation of new operator. The normal new operator performs two things. It allocates memory, and then constructs an object in allocated memory.The new operator allocates memory in the heap section and constructs objects there. But for the placement new operator, it constructs object at the given address. To deallocate memory, we can use delete keyword if the memory is allocated using new operator. But for placement new there is no placement delete feature.So in a nutshell, placement new allows you to ... Read More

In this section we will see what is the placement new operator in C++. This placement new is another variation of new operator. The normal new operator performs two things. It allocates memory, and then constructs an object in allocated memory.The new operator allocates memory in the heap section and constructs objects there. But for the placement new operator, it constructs object at the given address. To deallocate memory, we can use delete keyword if the memory is allocated using new operator. But for placement new there is no placement delete feature.So in a nutshell, placement new allows you to ... Read More

In this article we will see what is the conversion operator in C++. C++ supports object oriented design. So we can create classes of some real world objects as concrete types.Sometimes we need to convert some concrete type objects to some other type objects or some primitive datatypes. To make this conversion we can use conversion operator. This is created like operator overloading function in class.In this example we are taking a class for complex numbers. It has two arguments real and imaginary. When we assign the object of this class into some double type data, it will convert into ... Read More

In this article we will see how to add two numbers without using arithmetic operators like +, ++, -, or --.To solve this problem, we can solve them using binary adder logic. In that case we were designed half adder and full adder. These adders can add one bit binary numbers. By cascading multiple adders, we have can create circuit to add bigger numbers.In that adder, we have performed XOR operation among the numbers, then for the carry we were performing the ANDing logic. These features are implemented here to add two numbers.Example Code Live Demo#include using namespace std; int ... Read More

A hash table is a data structure which is used to store key-value pairs. Hash function is used by hash table to compute an index into an array in which an element will be inserted or searched.Linear probing is a collision resolving technique in Open Addressed Hash tables. In this method, each cell of a hash table stores a single key–value pair. If a collision is occurred by mapping a new key to a cell of the hash table that is already occupied by another key. This method searches the table for the following closest free location and inserts the ... Read More

Rolling hash is a hash function in which the input is hashed in a window that moves through the input.Rabin-Karp is popular application of rolling hash. The rolling hash function proposed by Rabin and Karp calculates an integer value. For a string the integer value is numeric value of a string.The Rabin–Karp string search algorithm is often explained using a very simple rolling hash function that only uses multiplications and additions −H=c1ak-1+c2ak-2+….+ cka0.Where, a is a constant, and c1, c2….ck are the input characters. In order to manipulate Huge value of H, mod n is done.AlgorithmBegin    Declare a constant ... Read More

A hash table is a data structure which is used to store key-value pairs. Hash function is used by hash table to compute an index into an array in which an element will be inserted or searched.Double hashing is a collision resolving technique in Open Addressed Hash tables. Double hashing uses the idea of using a second hash function to key when a collision occurs.This is a C++ program to Implement Hash Tables chaining with double hashing.AlgorithmFor search a key:Begin    Declare Function SearchKey(int k, HashTable *ht)       int hashVal= HashFunc1(k, ht->s)       int stepSize= HashFunc2(k, ... Read More