Happy Codings - Programming Code Examples
Html Css Web Design Sample Codes CPlusPlus Programming Sample Codes JavaScript Programming Sample Codes C Programming Sample Codes CSharp Programming Sample Codes Java Programming Sample Codes Php Programming Sample Codes Visual Basic Programming Sample Codes


C++ Programming Code Examples

C++ > Code Snippets Code Examples

Work with heaps: make_heap from vector

/* Work with heaps: make_heap from vector */ #include <iostream> #include <vector> #include <algorithm> using namespace std; int main() { vector<char> vectorObject; int i; for(i = 0; i <20; i+=2) vectorObject.push_back('A'+i); cout << "Sequence before building heap:"; for(i = 0; i <vectorObject.size(); i++) cout << vectorObject[ i ] << " "; cout << endl; make_heap(vectorObject.begin(), vectorObject.end()); cout << "Sequence after building heap:"; for(i = 0; i <vectorObject.size(); i++) cout << vectorObject[ i ] << " "; cout << endl; vectorObject.push_back('H'); push_heap(vectorObject.begin(), vectorObject.end()); cout << "Sequence after pushing onto heap:"; for(i = 0; i <vectorObject.size(); i++) cout << vectorObject[ i ] << " "; cout << endl; pop_heap(vectorObject.begin(), vectorObject.end()); cout << "Sequence after poping from heap:"; for(i = 0; i <vectorObject.size(); i++) cout << vectorObject[ i ] << " "; cout << endl; return 0; }

Return iterator to end. Returns an iterator referring to the past-the-end element in the vector container. The past-the-end element is the theoretical element that would follow the last element in the vector. It does not point to any element, and thus shall not be dereferenced. Because the ranges used by functions of the standard library do not include the element pointed by their closing iterator, this function is often used in combination with vector::begin to specify a range including all the elements in the container. If the container is empty, this function returns the same as vector::begin. This function does not accept any parameter.

A program shall contain a global function named main, which is the designated start of the program in hosted environment. main() function is the entry point of any C++ program. It is the point at which execution of program is started. When a C++ program is executed, the execution control goes directly to the main() function. Every C++ program have a main() function.

Return size. Returns the number of elements in the vector. This is the number of actual objects held in the vector, which is not necessarily equal to its storage capacity. vector::size() is a library function of "vector" header, it is used to get the size of a vector, it returns the total number of elements in the vector. The dynamic array can be created by using a vector in C++. One or more elements can be inserted into or removed from the vector at the run time that increases or decreases the size of the vector. The size or length of the vector can be counted using any loop or the built-in function named size(). This function does not accept any parameter.

Consider a situation, when we have two persons with the same name, jhon, in the same class. Whenever we need to differentiate them definitely we would have to use some additional information along with their name, like either the area, if they live in different area or their mother's or father's name, etc. Same situation can arise in your C++ applications. For example, you might be writing some code that has a function called xyz() and there is another library available which is also having same function xyz(). Now the compiler has no way of knowing which version of xyz() function you are referring to within your code.

Make heap from range. Rearranges the elements in the range [first,last) in such a way that they form a heap. The C++ algorithm::make_heap function is used to rearrange the elements in the range [first,last) in such a way that they form a max heap. A heap is a way to organize the elements of a range that allows for fast retrieval of the element with the highest value at any moment (with pop_heap), even repeatedly, while allowing for fast insertion of new elements (with push_heap). The element with the highest value is always pointed by first. The order of the other elements depends on the particular implementation, but it is consistent throughout all heap-related functions of this header.

In computer programming, loops are used to repeat a block of code. For example, when you are displaying number from 1 to 100 you may want set the value of a variable to 1 and display it 100 times, increasing its value by 1 on each loop iteration. When you know exactly how many times you want to loop through a block of code, use the for loop instead of a while loop. A for loop is a repetition control structure that allows you to efficiently write a loop that needs to execute a specific number of times.

Push element into heap range. push_heap() function is used to insert elements into heap. The size of the heap is increased by 1. New element is placed appropriately in the heap. Given a heap in the range [first,last-1), this function extends the range considered a heap to [first,last) by placing the value in (last-1) into its corresponding location within it. A range can be organized into a heap by calling make_heap. After that, its heap properties are preserved if elements are added and removed from it using push_heap and pop_heap, respectively. The function shall not modify any of its arguments. This can either be a function pointer or a function object. This function does not return any value.

In C++, vectors are used to store elements of similar data types. However, unlike arrays, the size of a vector can grow dynamically. That is, we can change the size of the vector during the execution of a program as per our requirements. Vectors are part of the C++ Standard Template Library. To use vectors, we need to include the vector header file in our program. The vector class provides various methods to perform different operations on vectors. Add Elements to a Vector: To add a single element into a vector, we use the push_back() function. It inserts an element into the end of the vector. Access Elements of a Vector: In C++, we use the index number to access the vector elements. Here, we use the at() function to access the element from the specified index.

Return iterator to beginning. Returns an iterator pointing to the first element in the vector. Notice that, unlike member vector::front, which returns a reference to the first element, this function returns a random access iterator pointing to it. If the container is empty, the returned iterator value shall not be dereferenced. The C++ function std::vector::begin() returns a random access iterator pointing to the first element of the vector. This function does not accept any parameter.

As the name already suggests, these operators help in assigning values to variables. These operators help us in allocating a particular value to the operands. The main simple assignment operator is '='. We have to be sure that both the left and right sides of the operator must have the same data type. We have different levels of operators. Assignment operators are used to assign the value, variable and function to another variable. Assignment operators in C are some of the C Programming Operator, which are useful to assign the values to the declared variables. Let's discuss the various types of the assignment operators such as =, +=, -=, /=, *= and %=. The following table lists the assignment operators supported by the C language:

#include is a way of including a standard or user-defined file in the program and is mostly written at the beginning of any C/C++ program. This directive is read by the preprocessor and orders it to insert the content of a user-defined or system header file into the following program. These files are mainly imported from an outside source into the current program. The process of importing such files that might be system-defined or user-defined is known as File Inclusion. This type of preprocessor directive tells the compiler to include a file in the source code program.

Pop element from heap range. Rearranges the elements in the heap range [first,last) in such a way that the part considered a heap is shortened by one: The element with the highest value is moved to (last-1). pop_heap() function is used to delete the maximum element of the heap. The size of heap is decreased by 1. The heap elements are reorganised accordingly after this operation. While the element with the highest value is moved from first to (last-1) (which now is out of the heap), the other elements are reorganized in such a way that the range [first,last-1) preserves the properties of a heap. A range can be organized into a heap by calling make_heap. After that, its heap properties are preserved if elements are added and removed from it using push_heap and pop_heap, respectively.

Add element at the end. Adds a new element at the end of the vector, after its current last element. The content of val is copied (or moved) to the new element. This effectively increases the container size by one, which causes an automatic reallocation of the allocated storage space if -and only if- the new vector size surpasses the current vector capacity. push_back() function is used to push elements into a vector from the back. The new value is inserted into the vector at the end, after the current last element and the container size is increased by 1. This function does not return any value.

Access element. Returns a reference to the element at position n in the vector container. A similar member function, vector::at, has the same behavior as this operator function, except that vector::at is bound-checked and signals if the requested position is out of range by throwing an out_of_range exception. Portable programs should never call this function with an argument n that is out of range, since this causes undefined behavior. Function returns the element at the specified position in the vector.


Two functions in this method. One is to print all nodes at a given level ("printGivenLevel"), and other is to "print level order traversal" of the tree ("printLevelorder"). printLevelorder






This C++ Program perform 'encoding matrix' using a hidden-key. "Encoding" is performed using "matrix multiplication" between given matrix and 'key matrix'. Enter the number of