I'm trying to sort a vector in C++, but the compiler says " 'sort' was not declared in this scope "

I’m doing a programming exercise that asks me to write a function that takes an array of integers and sorts it in this way: first puts all even integers sorted in ascending order, after that puts all the odd integers in descending order.

The code I wrote is the following:

#include <iostream>
#include <vector>
using namespace std;

void weirdSort(int v[], int n)
{
      vector<int> evenvec;           //My idea is to allocate two vectors which will collect
      vector<int> oddvec;            //the even integers separated from the odd ones
      int a = 0;                     
      int b = 0;                     //I use a and b to save the number of even and odd integers
      for(int i = 0; i < n; i++)
      {
            if(v[i]%2 == 0)
            {
                  evenvec.push_back(v[i]);
                  ++a;
            }
            else
            {
                  oddvec.push_back(v[i]);
                  ++b;
            }
      }
      sort(evenvec.begin(), evenvec.end());   //the compiler doesn't like this line
      sort(oddvec.begin(), oddvec.end()), greater<int>());
      for(int i = 0; i < a; i++)
            v[i] = evenvec[i];
      for(int i = 0; o < b; i++)
            v[i+a] = oddvec[i];
}         

>Solution :

Import std::sort with #include <algorithm>.