fast <- function(input, truth){

  input_clust <- outer(input,input,"==")
  truth_clust <- outer(truth,truth,"==")

  tp <- (input_clust & truth_clust)
  fp <- input_clust & !truth_clust
  tn <- !input_clust & !truth_clust
  fn <- !input_clust & truth_clust

  tp <- sum(tp & upper.tri(tp))
  fp <- sum(fp & upper.tri(fp))
  tn <- sum(tn & upper.tri(tn))
  fn <- sum(fn & upper.tri(fn))

  precision = 0
  recall = 0
  f_1 = 0

  if((tp>0)){
    precision = tp/(tp+fp)
  }
  if((tp>0)){
    recall = tp/(tp+fn)
  }
  if((precision > 0 & recall > 0)){
    f_1=(2*precision*recall)/(precision+recall)
  }

  return (c(precision,recall,f_1))
}