C++ Articles - Page 557 of 659

Dijkstra's algorithm (or Dijkstra's Shortest Path First algorithm, SPF algorithm) is an algorithm for finding the shortest paths between nodes in a graph, which may represent, for example, road networks. The algorithm creates a tree of shortest paths from the starting vertex, the source, to all other points in the graph.Dijkstra’s algorithm finds a shortest path tree from a single source node, by building a set of nodes that have minimum distance from the source.The graph has the following−vertices, or nodes, denoted in the algorithm by v or u.weighted edges that connect two nodes: (u, v) denotes an edge, and ... Read More

Catalan numbers are a sequence of numbers. Catalan numbers form a sequence of natural numbers that occur in various counting problems, often involving recursively-defined objects.Cn is the number of Dyck words of length 2n. A Dyck word is a string consisting of n X's and n Y's such that no initial segment of the string has more Y's than X's. For example, the following are the Dyck words of length 6XXXYYY XYXXYY XYXYXY XXYYXY XXYXYY.Re-interpreting the symbol X as an open parenthesis and Y as a close parenthesis, Cn counts the number of expressions containing n pairs of parentheses which ... Read More

A program to concatenate a string a given number of times will run the string concatenate method n number of times based on the value of n.The result would be string repeated a number of times.Examplegiven string: “ I love Tutorials point” n = 5OutputI love Tutorials pointI love Tutorials pointI love Tutorials pointI love Tutorials point I love Tutorials pointAfter seeing the output, it is clear that what the function will do.Example#include #include using namespace std; string repeat(string s, int n) {    string s1 = s;    for (int i=1; i

C++ Internals means how the working of C++ compiler compiling the .cpp code and giving us the output. C++ is a popular programming language mostly used for writing system software. It is an extension of the C programming language. C is a compiled language. The C++ compiler compiles C++ code to an object or executable file is generated. The executable or the binary files contains machine executable instructions and some metadata of the machine instructions.A typical way of compiling a C++ program is to run the compiler on C++ code. The compiler will generate machine instructions which are set of ... Read More

The mutable keyword in C++ is a storage class specifier. It enables non-static, non-const, and non-reference data members (i.e., mutable data member) of a class to be changed even when the object containing them is declared constant. Mutable data members are those members whose values can be changed in runtime even if the object is of constant type. It is just the opposite of a constant. What is Need of Mutable? Sometimes, it is necessary to modify one or more data members of a class/struct through the constant function, even if you do not want the function to update another ... Read More

Counting the number of trailing zeroes in a factorial number is done by counting the number of 2s and 5s in the factors of the number. Because 2*5 gives 10 which is a trailing 0 in the factorial of a number.ExampleFactorial of 7 = 5040, the number of trailing 0’s is 1.Based on our logic 7! = 2*3*4*5*6*7, it has 3 2s and 1 5s so the number of trailing 0’s is 1.#include using namespace std; int main() {    int n = 45;    int count = 0;    for (int i = 5; n / i >= 1; i *= 5)       count += n / i;    cout

Smallest K digit number that divisible by X is found using the formula by checking divisible by X. The formula works in the following way −Compute minimum K digit number [min] for example: 10/100/1000 etc.Now find if min is divisible by X. if yes, then this is the answer.If not, then min+X - ([min+X]%k) is the answer.Example#include #include using namespace std; int main() {    int X = 83;    int K = 5;    cout

Finding the number of vowels in a string using pointers need you to understand string, vowels and how to use pointer with string.String is an array of characters. And vowels are characters from the set {a, e, i, o, u}. Pointer is a variable that stores the value of memory location on a variable.To find the number of vowels in a string. We will traverse the string and then compare each character with vowels and if it is equal then it increase a counter otherwise not.Condition of the below code is that it requires a string that has all lowercase ... Read More

This program is used to find all the even factors and calculate the sum of these even factors and display it as output.Example −Input : 30 Even dividers : 2+6+10+30 = 48 Output : 48For this, we will find all the factors. Find the even of them and find the sum, Else, we will use the formula to find the sum of factors using the prime factors, Sum of divisors = (1 + d11 + d12 ... d1a1) *(1 + d21 + d22 ... d2a2) *...........................* (1 + dk1 + dk2 ... dkak) Here di = prime factors ; ai ... Read More

Here we will see some amazing results by using the system() function in C or C++. The system function is present in Windows, Linux and MAC operating systems. This function is used to execute the system commands that can be written in Command line.Here we will see two usages if system function in C or C++. The first one is getting the IP configuration details using C++ program.Example#include #include using namespace std; int main() {    system("C:\Windows\System32\ipconfig"); }OutputWindows IP Configuration Ethernet adapter Local Area Connection:    Connection-specific DNS Suffix . : domain.name    Link-local IPv6 Address . . ... Read More