Crear e inicializar un vector utilizando diferentes formas en STL C ++

C ++ STL | Crear e inicializar un vector : Aquí, vamos a aprender cómo crear un vector y cómo inicializar utilizando diferentes formas en STL C ++?

¿Cuál es el vector?

Vector es un contenedor en STL C ++, que se utiliza para representar la matriz y su tamaño se puede cambiar.

Leer más: C ++ STL vector

siguientes son las diferentes formas mediante el uso de ellos podemos crear e inicializar un vector de STL C ++,

1) Crear un vector vacío y initialize empujando los valores

//Create an empty vector and initialize by pushing values
  #include <iostream>
  #include <vector>
  using namespace std;
  int main()
  {
      //vector declaration
      vector<int> v1;
      //pushing the elements
      v1.push_back(10);
      v1.push_back(20);
      v1.push_back(30);
      v1.push_back(40);
      v1.push_back(50);
      //printing the vector elements
      //creating iterator to access the elements
      vector<int>::iterator it;
      cout << "Vector v1 elements are: ";
      for (it = v1.begin(); it != v1.end(); it++)
          cout << *it << " ";
      cout << endl;
      return 0;
  }
  

salida

Vector v1 elements are: 10 20 30 40 50
  

2) crear un vector mediante la especificación de los elementos de tamaño e inicializar con un valor class

//Create a vector by specifying the size and
  //initialize elements with a default value
  #include <iostream>
  #include <vector>
  using namespace std;
  int main()
  {
      //vector declaration
      vector<int> v1(5, 10);
      //printing the vector elements
      //creating iterator to access the elements
      vector<int>::iterator it;
      cout << "Vector v1 elements are: ";
      for (it = v1.begin(); it != v1.end(); it++)
          cout << *it << " ";
      cout << endl;
      return 0;
  }
  

salida

Vector v1 elements are: 10 10 10 10 10
  

3) Crear un vector y inicializarlo como un array

//Create a vector and initialize it like an array
  #include <iostream>
  #include <vector>
  using namespace std;
  int main()
  {
      //vector declaration
      vector<int> v1{ 10, 20, 30, 40, 50 };
      //printing the vector elements
      //creating iterator to access the elements
      vector<int>::iterator it;
      cout << "Vector v1 elements are: ";
      for (it = v1.begin(); it != v1.end(); it++)
          cout << *it << " ";
      cout << endl;
      return 0;
  }
  

salida

Vector v1 elements are: 10 20 30 40 50
  

4) crear un vector y inicializarlo de una matriz

//Create a vector and initialize it from an array
  #include <iostream>
  #include <vector>
  using namespace std;
  int main()
  {
      //array
      int arr[] = { 10, 20, 30, 40, 50 };
      //vector declaration from the array
      //array size
      int size = sizeof(arr) / sizeof(arr[0]);
      vector<int> v1(arr, arr + size);
      //printing the vector elements
      //creating iterator to access the elements
      vector<int>::iterator it;
      cout << "Vector v1 elements are: ";
      for (it = v1.begin(); it != v1.end(); it++)
          cout << *it << " ";
      cout << endl;
      return 0;
  }
  

salida

Vector v1 elements are: 10 20 30 40 50
  

5) crear un vector e inicializar desde otro vector

//Create a vector and initialize it from another vector
  #include <iostream>
  #include <vector>
  using namespace std;
  int main()
  {
      //vector
      vector<int> v1{ 10, 20, 30, 40, 50 };
      //vector declaration from the vector
      vector<int> v2(v1.begin(), v1.end());
      //printing the vector elements
      //creating iterator to access the elements
      vector<int>::iterator it;
      cout << "Vector v2 elements are: ";
      for (it = v2.begin(); it != v2.end(); it++)
          cout << *it << " ";
      cout << endl;
      return 0;
  }
  

salida

Vector v2 elements are: 10 20 30 40 50