Max in O(n)

#include <iostream>
#include <vector>
using namespace std;
int main( ) {
    int d;

    cout<<"Enter nunber of elements: ";
    cin>>d;
    vector <int> myVector(d);
    int sum=0;

    for(unsigned int i=0;i<myVector.size();i++){
    cin>>myVector[i];
    }
    //myVector.insert(myVector.begin() )
    cout<<endl;
    int max= myVector[0];
    for(unsigned int i=1;i<myVector.size();i++){
    if (max<myVector[i]){
        max=myVector[i];
    }
    }
    cout<<max;
    return 0;
}