function unique(arr){
  return [...new Set(arr)];
}

function unique(arr){
  let res = [];
  let obj = new Object();
  arr.forEach(e => {
      if(!obj[e]){
          obj[e] = 1;
          res.push(e);
      }
  });
  return res;
}

function unique(arr){
    let seen = [];
    arr.forEach(e => {
        if(seen.indexOf(e) < 0){
            seen.push(e);
        }
    });
    return seen;
  }
console.log(unique([1,1,1,1,3,4]));

def unique(arr):
  seen = []
  for i in arr:
    if i not in seen:
      seen.append(i)
  return seen

  # include<iostream>
  # include<cstring>
  # include<cstdlib>
  using namespace std;
  int* unique(int arr[]){
      int seen[] = ;
  }
  int main(){
    int arr[] = {1,1,1,1,1,3,4};
    const int n = sizeof(arr) / sizeof(*arr);
    unique(arr);
    for(int i=0;i<n;i++){
        cout<<arr[i]<<endl;
    }
    return 0;
  }