Untitled

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

void merge(vector<int> &a, vector<int> &b, vector<int> &res) {
    int i = 0;
    int j = 0;
    int k = 0;
    while (i < a.size() && j < b.size()) {
        if (a[i] < b[j]) {
            res[k] = a[i];
            i++;
            k++;
        } else {
            res[k] = b[j];
            j++;
            k++;
        }
    }
    if (i == a.size()) {
        while (j < b.size()) {
            res[k] = b[j];
            j++;
            k++;
        }
    }
    if (j == b.size()) {
        while (i < a.size()) {
            res[k] = a[i];
            i++;
            k++;
        }
    }
}

void merge_sort(vector<int> &v) {
    int n = v.size();
    if (n == 1) return;
    int n1 = n / 2;
    int n2 = n - n / 2;
    vector<int> a(n1);
    vector<int> b(n2);
    for (int i = 0; i < n1; i++) {
        a[i] = v[i];
    }
    for (int i = 0; i < n2; i++) {
        b[i] = v[i + n1];
    }
    merge_sort(a);
    merge_sort(b);
    merge(a, b, v);
}

int main() {
    int arr[] = {1, 4, 5, 7, 3, 5};
    int n = sizeof(arr) / sizeof(arr[0]);
    vector<int> v(arr, arr + n);
    for (int i = 0; i < v.size(); i++) {
        cout << v[i] << " ";
    }
    cout << endl;
    merge_sort(v);
    for (int i = 0; i < v.size(); i++) {
        cout << v[i] << " ";
    }
    return 0;
}