Question

C++ question.

Introduce a pass by pointer function that reverses a whole vector.

Answer 1

#include <iostream>
#include <vector>

using namespace std;

void printVector(const vector<int> &v) {
    for (size_t i = 0; i < v.size(); i++) {
        cout << v[i] << " ";
    }
    cout << endl;
}

void reverse(vector<int> *v) {
    int temp;    // temp variable for swapping data
    for (int i = 0; i < v->size() / 2; ++i) {    // iterate until half of the array
        temp = (*v)[i];
        (*v)[i] = (*v)[v->size() - i - 1];
        (*v)[v->size() - i - 1] = temp;    // swap
    }
}

int main() {
    vector<int> v = {1, 4, 9, 16, 9, 7, 4, 9, 11};
    cout << "Original vector: ";
    printVector(v);
    reverse(&v); // reverse the vector
    cout << "Reversed vector: ";
    printVector(v);
    return 0;
}