C++ Programming Code Examples
C++ > Code Snippets Code Examples
Using copy() in Vector
/* Using copy() in Vector */
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
vector<char> vectorObject(10);
vector<char> vectorObject2(10);
int i;
for(i = 0; i < 10; i++)
vectorObject[ i ] = 'A' + i;
for(i = 0; i < 10; i++)
vectorObject2[ i ] = 'z';
copy(vectorObject.begin(), vectorObject.end(), vectorObject2.begin()); // copy all of vectorObject into vectorObject2
cout << "Contents of vectorObject2 after copy:\n";
for(i = 0; i < 10; i++)
cout << vectorObject2[ i ] << " ";
cout << endl;
for(i = 0; i <10; i++) // re-initialize vectorObject2
vectorObject2[ i ] = 'z';
copy(vectorObject.begin() + 2, vectorObject.end() - 2, vectorObject2.begin()); // now copy just part of vectorObject into vectorObject2
cout << "Contents of vectorObject2 after subsequence copy:\n";
for(i = 0; i <10; i++)
cout << vectorObject2[ i ] << " ";
cout << endl;
for(i = 0; i <10; i++) // re-initialize vectorObject2
vectorObject2[ i ] = 'z';
// now copy part of vectorObject into middle of vectorObject2
copy(vectorObject.begin() + 2, vectorObject.end() - 2, vectorObject2.begin() + 3);
cout << "Contents of vectorObject2 after copy into middle:\n";
for(i = 0; i <10; i++)
cout << vectorObject2[ i ] << " ";
cout << endl;
return 0;
}
#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.
copy() function is used to copy items from one iterator to another iterator with a specific range. We can define the start and end position of the source and it will copy all items in this rage to a different destination. To use copy() function, we need to include <bits/stdc+.h> or header file. It copies all the elements pointed by first and last. first element is included in the output but last is not. output is the start position of the final result iterator. It returns one iterator to the end of the destination range where elements have been copied. Function returns an iterator to the end of the destination range where elements have been copied.
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.
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.
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.
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.
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.
Ask to enter two time periods and these two periods are stored in structure variables t1 t2 respectively. The computeTimeDifference() Function calculates the Difference Between
To find the LCM of 2 or more numbers, make "Multiple of Numbers" and Choose Common multiple. Then take lowest common multiple, lowest common multiple is 'LCM' of numbers.
