C++ Articles - Page 611 of 717

The subsets of a set refers to all the possible combinations of choosing elements from the set. For example, if we have a set {1, 2}, the subsets are {}, {1}, {2}, and {1, 2}. In this article, we will learn how to generate subsets of a set using the Binary Counting Method in C++. // Set of elements int arr[] = {1, 2, 3}; // Subsets of the above set {}, {1}, {2}, {3}, {1, 2}, {1, 3}, {2, 3}, {1, 2, 3} Binary Counting Method The binary counting method is a technique used to generate ... Read More

This is a C++ program to implement the Alexander Bogomolny’s UnOrdered Permutation Algorithm for elements from 1 to NAlgorithmsBegin    function AlexanderBogomolny() to implement the Algorithms    Arguments:       Val[] = an array       N = number of elements taken as input.       K = level       Body of the function:       intialize l = -1       l = l+1       Val[k] = l       if (l == N)          Call function display(Val, N)       else       ... Read More

In this article, our task is to find the number of occurrences of a given number using binary search. The binary search algorithm works on the divide-and-conquer principle as it keeps dividing the array in half before searching. To search for an element in an array using binary search, it should be sorted. In the sorted array, we find the middle element and compare it with the element that has to be searched, and based on the comparison, we either search in the left or right sub-array or return the middle element. Following are some example scenarios: Scenario ... Read More

In C we can pass parameters in two different ways. These are call by value, and call by address, In C++, we can get another technique. This is called Call by reference. Let us see the effect of these, and how they work.First we will see call by value. In this technique, the parameters are copied to the function arguments. So if some modifications are done, that will update the copied value, not the actual value.Example#include using namespace std; void my_swap(int x, int y) {    int temp;    temp = x;    x = y;    y = ... Read More

In C or C++, we have used the switch-case statement. In the switch statement we pass some value, and using different cases, we can check the value. Here we will see that we can use ranges in the case statement.The syntax of using range in Case is like below −case low … highAfter writing case, we have to put lower value, then one space, then three dots, then another space, and the higher value.In the following program, we will see what will be the output for the range based case statement.Example#include main() {    int data[10] = { 5, ... Read More

Sometimes we see that there are two types of main function definition. The int main() and int main(void). So is there any difference?In C++, there is no difference. In C also both are correct. But the second one is technically better. It specifies that the function is not taking any argument. In C if some function is not specified with the arguments, then it can be called using no argument, or any number of arguments. Please check these two codes. (Remember these are in C not C++)Example#include void my_function() {    //some task } main(void) {    my_function(10, "Hello", "World"); ... Read More

In some cases we use long long in C or C++. Here we will see what is basically long long is? The long long takes twice as much memory as long. In different systems, the allocated memory space differs. On Linux environment the long takes 64-bit (8-bytes) of space, and the long long takes 128-bits (16-bytes) of space. This is used when we want to deal with some large value of integers.We can test the size of different types using this simple program.Example#include using namespace std; main() {    int a;    long b;    long long c;    cout

Here we will see how to convert bool to int equivalent in C++. Bool is a datatype in C++, and we can use true or false keyword for it. If we want to convert bool to int, we can use typecasting. Always true value will be 1, and false value will be 0.Example#include using namespace std; main() {    bool my_bool;    my_bool = true;    cout

Here we will see how to check whether a given input is integer string or a normal string. The integer string will hold all characters that are in range 0 – 9. The solution is very simple, we will simply go through each characters one by one, and check whether it is numeric or not. If it is numeric, then point to the next, otherwise return false value.Example#include using namespace std; bool isNumeric(string str) {    for (int i = 0; i < str.length(); i++)       if (isdigit(str[i]) == false)       return false; //when one ... Read More

To create high resolution timer we can use the chrono library. This library has high resolution clock. This can count in nanoseconds.In this program we will see the execution time in nanoseconds. We will take the time value at first, then another time value at the last, then find the difference to get elapsed time. Here we are using blank loop to pause the effect for sometimes.Example#include #include typedef std::chrono::high_resolution_clock Clock; main(){    auto start_time = Clock::now();    for(int i = 0; i