std::vector in Depth

The Workhorse Container

#include <vector>

vector<int> v;
v.push_back(10);   // append
v.push_back(20);
v.push_back(30);

v.size()           // 3
v.front()          // 10
v.back()           // 30
v.pop_back()       // removes 30

v.insert(v.begin()+1, 15);  // insert at position
v.erase(v.begin());          // remove first element
v.clear();

Initializations

vector<int> a = {1,2,3,4,5};
vector<int> b(5, 0);           // five zeros
vector<int> c(a.begin(), a.begin()+3);  // {1,2,3}

Your Task

Write removeDuplicates(vector<int> v) that returns a new vector with duplicates removed, preserving order of first occurrence.
Example: {1,2,2,3,1,4} → {1,2,3,4}