inputs <- c('dbbaCEDbdAacCEAadcB', 'EbAAdbBEaBaaBBdAccbeebaec')

tally <- function(input) {
  letters <- unlist(strsplit(input, ''))
  hash <- new.env()

  # Tally scores.
  sapply(letters, function(letter) {
    # If the letter is not uppercase it's a score. Otherwise, it's a loss.
    score <- ifelse(gregexpr("[A-Z]", letter) < 1, 1, -1)

    letter <- tolower(letter)
    hash[[letter]] <- ifelse(is.null(hash[[letter]]), score, hash[[letter]] + score)
  })

  # Get score values.
  scores <- c()
  keys <- ls(hash)
  scores <- t(sapply(keys, function(key) {
    c(scores, c(key, hash[[key]]))
  }))
  colnames(scores) <- c('player', 'score')
  scores <- as.data.frame(scores)
  scores$score <- as.numeric(as.character(scores$score))

  # Sort the scores.
  scores[order(scores$score, decreasing=T),]
}

format <- function(scores) {
  str <- sapply(1:nrow(scores), function(i) {
    row <- scores[i,]
    paste0(row$player, ':', row$score)
  })

  str
}