vector::rbegin() is a built-in function in C++ STL which returns a reverse iterator pointing to the last element in the container.
Syntax:
vector_name.rbegin()
Parameters: The function does not accept any parameter.
Return value: The function returns a reverse iterator pointing to the last element in the container.
Program to demonstrate the vector::rbegin() method:
Program 1:
// CPP program to illustrate // the vector::rbegin() function #include <bits/stdc++.h> using namespace std;
int main()
{ vector< int > v;
v.push_back(11);
v.push_back(12);
v.push_back(13);
v.push_back(14);
v.push_back(15);
// prints all the elements
cout << "The vector elements in reverse order are:\n";
for ( auto it = v.rbegin(); it != v.rend(); it++)
cout << *it << " ";
return 0;
} |
The vector elements in reverse order are: 15 14 13 12 11
Time Complexity – constant O(1)
vector::rend() is a built-in function in C++ STL which returns a reverse iterator pointing to the theoretical element right before the first element in the vector container.
Syntax:
vector_name.rend()
Parameters: The function does not take any parameter.
Return value: The function returns a reverse iterator pointing to the theoretical element right before the first element in the vector container.
Program to demonstrate the vector::rend() method:
Program 1:
// CPP program to illustrate // the vector::rend() function #include <bits/stdc++.h> using namespace std;
int main()
{ vector< int > v;
v.push_back(11);
v.push_back(12);
v.push_back(13);
v.push_back(14);
v.push_back(15);
cout << "The last element is: " << *v.rbegin();
// prints all the elements
cout << "\nThe vector elements in reverse order are:\n";
for ( auto it = v.rbegin(); it != v.rend(); it++)
cout << *it << " ";
return 0;
} |
The last element is: 15 The vector elements in reverse order are: 15 14 13 12 11
Time Complexity – constant O(1)