vector<int&> a；int b=1；a.push_back（b）；b=2；printf“%d”，a［0］；这段代码存在bug，请改正

> is a data structure in C++ that represents a dynamic array i.e. an array whose size can change during runtime. It is part of the Standard Template Library (STL) and is included in the <vector> header file.

A vector<int> can be declared and initialized as follows:

#include <vector>

std::vector<int> myVector {1, 2, 3, 4, 5};

This creates a vector with 5 integer elements: 1, 2, 3, 4, and 5.

Vectors have several useful methods such as push_back(), which adds an element to the end of the vector:

myVector.push_back(6);

This adds the integer 6 to the end of the vector.

Vectors can also be accessed using the subscript operator []:

int secondElement = myVector[1];

This retrieves the second element in the vector, which is 2.

Overall, vectors are a convenient and flexible data structure for storing and manipulating collections of integers.