Table of Contents
Introduction
In this article we will learn c++ vector remove nth element. Vectors are a part of the c++ STL library. They are containers but can change memory at runtime. Which can be very useful in memory and space management of programs.
Vectors
Vectors are a part of Standard Template Library (STL) in C++ which is a general purpose library used to store and retrieve continuous data. Vectors are similar to arrays but they change their size during runtime. C++ and Java are one of the few general purpose high level languages which help in memory management.
How to initialize a vector ?
Include the vector library
#include<vector>
Initialize vector
vector<int> v;
Vectors have some built in functions, some most important ones are :
push_back()to insert data at the end.begin()shows the starting point of the vector.end()shows the end of the vector.size()returns the size of the vector.capacity()shows the capacity of the vector.resize()it resize the vector to the desirable size.
Lets look at a code example of how all these functions work
// c++ vector remove nth element
#include <vector>
#include <iostream>
using namespace std;
int main()
{
vector<int> v;
int i;
for (i = 0; i < 10; i++)
v.push_back(i);
v.erase(v.begin() + 5);
for (i = 0; i < v.size(); i++)
cout << v[i] << " ";
cout << endl;
//size of vector
cout << "size of vector: " << v.size() << endl;
//capacity of vector
cout << "capacity of vector: " << v.capacity() << endl;
//resize vector
v.resize(5);
cout << "size of vector: " << v.size() << endl;
//begin
cout << "begin: " << *v.begin() << endl;
//end
cout << "end: " << *v.end() << endl;
//max size
cout << "max size: " << v.max_size() << endl;
return 0;
}Output of this code is :
0 1 2 3 4 6 7 8 9
size of vector: 9
capacity of vector: 16
size of vector: 5
begin: 0
end: 6
max size: 2305843009213693951
Solution: c++ vector remove nth element
We will now look at how c++ vector remove nth element . one way is to add the nth element to the start and erase that element.
Lets look at the code :
// c++ vector remove nth element
#include <vector>
#include <iostream>
using namespace std;
int main()
{
vector<int> v;
int i;
for (i = 0; i < 10; i++)
v.push_back(i);
for (i = 0; i < v.size(); i++)
cout << v[i] << " ";
cout << endl;
// // remove the nth element
int n;
cout << "Enter the element to be removed: ";
cin >> n;
v.erase(v.begin() + n);
for (i = 0; i < v.size(); i++)
cout << v[i] << " ";
return 0;
}Output :
The vector is 0 1 2 3 4 5 6 7 8 9
Enter the element to be removed: 4
0 1 2 3 5 6 7 8 9
Conclusion
In this article we learned c++ vector removes nth element. How we can add elements to a vector, how we can access it, how we can erase an element to a vector. We studied the in-built functions of the vectors like size, capacity, begin, and end.
Further Reading
