C++ Articles - Page 619 of 717

Sometimes we can find the keyword ‘const’ present at the last of function declaration. So what does it mean?Using this one function can be made as constant. The idea of constant function is that, the function cannot be modified from the objects, where they are called. It is recommended to use the constant functions in our program.Let us see one example of constant function.Example#include using namespace std; class MyClass {    int value;    public:       MyClass(int val = 0) {          value = val;       }       int getVal() const ... Read More

Here we will see how to initialize the private static member variables initialization in C++. We can put static members (Functions or Variables) in C++ classes. For the static variables, we have to initialize them after defining the class.To initialize we have to use the class name then scope resolution operator (::), then the variable name. Now we can assign some value.The following code will illustrate the of static member initializing technique.Example#include using namespace std; class MyClass{    private:       static int st_var;    public:       MyClass(){          st_var++; //increase the value ... Read More

The Baillie-PSW Primality Test, this test named after Robert Baillie, Carl Pomerance, John Selfridge, and Samuel Wagstaff. It is a test which tests whether a number is a composite number or possibly prime.AlgorithmMillerTest()Begin    Declare a function MillerTest of Boolean type.    Declare MT_dt and MT_num of integer datatype and pass as the parameter.    Declare MT_a and MT_x of integer datatype.       Initialize MT_a = 2 + rand( ) % (MT_num - 4).       Initialize MT_x = pow(MT_a, MT_dt, MT_num).    if (MT_x == 1 || MT_x == MT_num - 1) then       ... Read More

Solovay-Strassen Primality Test is used to test a number whether it is a composite or possibly prime number.AlgorithmsBegin    Declare a function modulo to the long datatype to perform binary calculation.       Declare m_base, m_exp, m_mod of long datatype and pass them as a parameter.       Declare two variables a, b of long datatype.          Initialize a = 1, b = m_base.       while (m_exp > 0) do          if (m_exp % 2 == 1) then             a = (a * b) % ... Read More

To find the Vertex Connectivity of a graph we need to find out Articulation Points of that graph. Articulation Points (or Cut Vertices) in a Graph is a point iff removing it (and edges through it) disconnects the graph. An articulation point for a disconnected undirected graph, is a vertex removing which increases number of connected components.AlgorithmBegin    We use dfs here to find articulation point:    In DFS, a vertex w is articulation point if one of the following two conditions is satisfied.    1) w is root of DFS tree and it has at least two children.   ... Read More

In this program to find the maximum Cut in a graph, we need to find the Edge Connectivity of a Graph. An Edge Connectivity of a Graph of a graph means it is a bridge, removing it graph will be disconnected. Number of connected components increases with the removing of bridge in a disconnected undirected graph.Functions and pseudocodeBegin    Function connections() is a recursive function to find out the connections:    A) Mark the current node un visited.    B) Initialize time and low value    C) Go through all vertices adjacent to this    D) Check if the subtree ... Read More

Weakly or Strongly Connected for a given a undirected graph can be found out using DFS. This is a C++ program of this problem.Functions usedBegin Function fillorder() = fill stack with all the vertices.    a) Mark the current node as visited and print it    b) Recur for all the vertices adjacent to this vertex    c) All vertices reachable from v are processed by now, push v to Stack End Begin Function DFS() :    a) Mark the current node as visited and print it    b) Recur for all the vertices adjacent to this vertex EndExample#include ... Read More

Weakly or Strongly Connected for a given a directed graph can be found out using DFS. This is a C++ program of this problem.Functions usedBegin Function fillorder() = fill stack with all the vertices.    a) Mark the current node as visited and print it    b) Recur for all the vertices adjacent to this vertex    c) All vertices reachable from v are processed by now, push v to Stack End Begin Function DFS() :    a) Mark the current node as visited and print it    b) Recur for all the vertices adjacent to this vertex EndExample#include ... Read More

A Hamiltonian cycle is a Hamiltonian Path such that there is an edge (in graph) from the last vertex to the first vertex of the Hamiltonian Path. It is in an undirected graph is a path that visits each vertex of the graph exactly once.Functions and purposesBegin    1. function isSafe() is used to check for whether it is    adjacent to the previously added vertex and already not added.    2. function hamiltonianCycle() solves the hamiltonian problem.    3. function hamCycle() uses hamiltonianCycle() to solve    the hamiltonian problem. It returns false if there is no    Hamiltonian Cycle ... Read More

In this Program we will basically find a feedback arc set which contains edges which when removed from the graph, graph becomes directed acyclic graph.AlgorithmBegin function checkCG(int n) : n: number of vertices. arr: struct graph variable. Initialize cnt = 0 and size = (n-1). For i =0 to n-1    if (cnt == size)       return 0    if (arr[i].ptr == NULL)       Increase cnt.       for j = 0 to n-1          while (arr[j].ptr != NULL)             if ((arr[j].ptr)->des == (arr[i].ptr)->des)       ... Read More