First and last occurrences of x

// { Driver Code Starts
#include<bits/stdc++.h>
using namespace std;
vector<int> find(int a[], int n , int x );

int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        int n,x;
        cin>>n>>x;
        int arr[n],i;
        for(i=0;i<n;i++)
        cin>>arr[i];
        vector<int> ans;
        ans=find(arr,n,x);
        cout<<ans[0]<<" "<<ans[1]<<endl;
    }
    return 0;
}


// } Driver Code Ends


vector<int> find(int arr[], int n , int x )
{
    // code here
    int lo = lower_bound(arr, arr + n, x) - arr;
    int up = upper_bound(arr, arr + n, x) - arr;
    vector<int> v;
    if (lo == n) {
        v.push_back(-1);
        v.push_back(-1);
        return v;
    }
    if (arr[lo] != x) {
        v.push_back(-1);
        v.push_back(-1);
        return v;
    }
    v.push_back(lo);
    v.push_back(up - 1);
    return v;
}