Sum of Three Values

bool find_sum_of_three(vector<int> arr,
  int required_sum) {
  // TODO: Write - Your - Code
  return false;
}

bool find_sum_of_two(vector<int>& A, int val,
  size_t start_index) {
  for (int i = start_index, j = A.size() - 1; i < j;) {
    int sum = A[i] + A[j];
    if (sum == val) {
      return true;
    }
    if (sum < val) {
      ++i;
    } else {
      --j;
    }
  }
  return false;
}
bool find_sum_of_three_v3(vector<int> arr,
  int required_sum) {
  std::sort(arr.begin(), arr.end());
  for (int i = 0; i < arr.size() - 2; ++i) {
    int remaining_sum = required_sum - arr[i];
    if (find_sum_of_two(arr, remaining_sum, i + 1)) {
      return true;
    }
  }
  return false;
}
int main(){
    vector<int> arr = {-25, -10, -7, -3, 2, 4, 8, 10};
  
    cout<<"-8: " <<find_sum_of_three_v3(arr, -8)<<endl; 
    cout<<"-25: "<<find_sum_of_three_v3(arr, -25)<<endl;
    cout<<"0: " <<find_sum_of_three_v3(arr, 0)<<endl;
    cout<<"-42: " <<find_sum_of_three_v3(arr, -42)<<endl; 
    cout<<"22: " <<find_sum_of_three_v3(arr, 22)<<endl; 
    cout<<"-7: " <<find_sum_of_three_v3(arr, -7)<<endl;
    cout<<"-3: " <<find_sum_of_three_v3(arr, -3)<<endl; 
    cout<<"2: " <<find_sum_of_three_v3(arr, 2)<<endl; 
    cout<<"4: " <<find_sum_of_three_v3(arr, 4)<<endl; 
    cout<<"8: " <<find_sum_of_three_v3(arr, 8)<<endl; 
    cout<<"7: " <<find_sum_of_three_v3(arr, 7)<<endl; 
    cout<<"1: " <<find_sum_of_three_v3(arr, 1)<<endl;
  
    return 0;
}