how to reverse specific portion of vector code example

Example 1: c++ reverse vector

#include <bits/stdc++.h> // Vector
#include <algorithm>  // Reverse 
using namespace std;

int main()
{
    vector<int> nums{4,1,2,1,2};

    reverse(nums.begin(), nums.end());
    return 0;
}

Example 2: how to reverse a vector

//vector<int> A;
reverse(A.begin(),A.end());

Example 3: reverse a vector

vector<int> a = {1,2,3,4,5,6};
reverse(a.begin(), a.end());