vector function in c++ code example
Example 1: how to use vectors c++
#include <iostream>
#include <vector>
using namespace std;
int main() {
const int size = 4;
vector<int> myVect (size, 4);
for (int i=0; i<size; i++) {
cout << "Vector index(" << i <<") is: "<< myVect[i] << endl;
}
return 0;
}
Example 2: vector functions c++
Iterators
-----------------------------------------
begin | Returns an iterator to the beginning
end | Returns an iterator to the end
Capacity
-----------------------------------------
empty | Checks whether the container is empty
size | Returns the number of elements
reserve | Reserves storage
capacity | Returns the number of elements that can be held in currently allocated storage
Element access
-----------------------------------------
at | Access specified element with bounds checking
front | Access the first element
back | Access the last element
operator[] | Access specified element
Modifiers
-----------------------------------------
clear | Clears the contents
insert | Inserts elements
emplace | Constructs element in-place
erase | Erases elements
push_back | Adds an element to the end
emplace_back | Constructs an element in-place at the end
pop_back | Removes the last element
resize | Changes the number of elements stored
swap | Swaps the contents
*Notes*
- https:
- https:
- https:
Example 3: vector operations in c++
#include <iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main()
{
int n;
cin>>n;
vector<int>vec(n);
for(int i=0;i<n;i++)
{
cin>>vec[i];
}
cout<<"----------"<<endl;
for(int i=0;i<n;i++)
{
cout<<vec[i]<<" ";
}
vec.push_back(100);
vec.push_back(200);
cout<<endl;
auto it=vec.begin();
vec.insert(it,3,1000);
for(vector<int>::iterator it1=vec.begin();it1!=vec.end();it1++)
{
cout<<*it1<<" ";
}
cout<<endl;
vector<int>vec2;
vec2.push_back(15);
vec2.push_back(25);
vec2.push_back(35);
vec.insert(it,vec2.begin(),vec2.end());
for(vector<int>::iterator it1=vec.begin();it1!=vec.end();it1++)
{
cout<<*it1<<" ";
}
cout<<endl;
vec.pop_back();
vec.pop_back();
for(vector<int>::iterator it1=vec.begin();it1!=vec.end();it1++)
{
cout<<*it1<<" ";
}
cout<<endl;
int k;
cin>>k;
cout<<endl;
vector<int>::iterator its=vec.begin()+k-1;
int s=vec.size();
cout<<s<<endl;
vec.erase(its);
for(vector<int>::iterator it1=vec.begin();it1!=vec.end();it1++)
{
cout<<*it1<<" ";
}
return 0;
}