Find element using binary search and sort using insertion sort

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

void insertionsort(int arr[],int n)
{
    for (int i = 1; i < n; i++)
    {
        int key = arr[i];
        int j = i - 1;
        while (j >= 0 && arr[j] > key)
        {
            arr[j + 1] = arr[j];
            j = j - 1;
        }
        arr[j + 1] = key;
    }
}

void binarysearch(int arr[],int n, int key)
{
    int low = 0, high = n-1;
    bool flag = false;
    while(low<=high)
    {
        int mid = (high+low)/2;
        if(arr[mid]==key)
        {
            flag = true;
            break;
        }
        if(arr[mid]<key)
            low = mid+1;
        else if(arr[mid]>key)
            high = mid-1;
    }
    if(flag)
        cout << "Found" << endl;
    else
        cout << "Not Found" << endl;
}

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

    int n;
    cin >> n;
    int arr[n];
    for(int i=0;i<n;i++)
        cin >> arr[i];
    //insertion sort
    insertionsort(arr,n);
    for(int i=0;i<n;i++)
        cout << arr[i] << " ";
    cout << endl;

    int key;
    cin >> key;
    binarysearch(arr,n,key);


    return 0;
}