Merge Sort(Adv Cmp Class)

#include<bits/stdc++.h>
using namespace std;
const int mx = 1e9+7;
int tmp[mx];
int final[mx];
void merge_sort(int l, int r){
    if(l>=r) return;
    int mid = (l+r)/2;
    merge_sort(l, mid);
    merge_sort(mid+1, r);
    for(int i = l, lo = l, hi = mid+1; i<= r; i++){
        if(lo==mid+1){
            tmp[i] = final[hi++];
        }
        else if(hi==r){
            tmp[i] = final[lo++];
        }
        else if(final[lo]<final[hi]){
            tmp[i] = final[lo++];
        }
        else{
            tmp[i] = final[hi++];
        }
    }
    for(int i = l; i<=r; i++) final[i] = tmp[i];
    
}
void solution(){
    int n; cin>>n;
    vector<int> vct(n);
    for(int i = 0; i<n; i++){
        cin>>vct[i];
    }
    merge_sort(0, n-1);
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif    

    solution();
}