primaryobjects · November 6, 2017 19:17
diff --git a/cannibal.R b/cannibal.R
 #
 # [2017-10-16] Challenge #336 [Easy] Cannibal numbers
 # https: https://www.reddit.com/r/dailyprogrammer/comments/76qk58/20171016_challenge_336_easy_cannibal_numbers/
 #
 # Demo at http://www.r-fiddle.org/#/fiddle?id=xqqeOaS1&version=2
 #
 # Imagine a given set of numbers wherein some are cannibals.
 # We define a cannibal as a larger number can eat a smaller number and increase its value by 1.
 # There are no restrictions on how many numbers any given number can consume.
 # A number which has been consumed is no longer available.
 # Your task is to determine the number of numbers which can have a value equal to or greater than a specified value.
 #
 # by Kory Becker
 # http://primaryobjects.com
 #

 cannibalize <- function(input, threshold, verbose=F) {
  # Start by counting the numbers that are already >= query.
  count <- length(input[input >= threshold])
  
  if (verbose) print(paste(count, "number(s) already meet the threshold."))
  
  # Sort the numbers in descending order.  
  numbers <- sort(input[input < threshold], T)
  numbersAsc <- sort(input[input < threshold], F)
  
  # Use the indices of each number to record consumptions.  
  indices <- seq_along(numbers)
  indicesAsc <- rev(indices)
  
  consumed <- c()
  
  # For each number, find the smallest numbers to add to make them >= to the query value.
  sapply(indices, function(i) {
    if (!i %in% consumed) {
      number <- numbers[i]
      
      total <- number
      
      for (j in indicesAsc) {
        if (!j %in% consumed) {
          n <- numbers[j]
          
          # A number can't consume itself and must be bigger than the prey.
          if (i != j && total > n) {
            # Consume it.
            total <- total + 1
            
            if (verbose) print(paste(number, "is trying to consume", n, "for a total of", total))
            
            # Mark the index as consumed.
            consumed <<- c(consumed, j)
            
            if (total >= threshold) {
              if (verbose) print('Consumed!')
              count <<- count + 1
              break
            }
          }
        }
      }
    }
  })
  
  count
 }

 # Our input data.
 data <- list(
  list(numbers = c(21, 9, 5, 8, 10, 1, 3), queries = c(10, 15), answers = c(4, 2)),
  list(numbers = c(1, 2, 3, 4, 5), queries = c(5), answers = c(2)),
  list(numbers = c(9, 10, 14, 15, 18, 21, 4, 3, 7, 8, 10, 12), queries = c(9:13), answers = c(9, 9, 8, 7, 6)),
  list(numbers = c(4, 4, 4, 4, 4, 4, 4), queries = c(5), answers = c(0)),
  list(numbers = c(5, 4, 4, 4, 1), queries = c(6), answers = c(1)),
  list(numbers = c(2, 2, 2, 2), queries = c(3), answers = c(0)),
  list(numbers = c(4, 4, 4, 3), queries = c(6), answers = c(1)),
  list(numbers = c(3, 3, 3, 3), queries = c(4), answers = c(0))
 )

 # Run the canibal numbers method on each problem set.
 x <- sapply(data, function(row) {
  # Get the result for this problem set.
  results <- sapply(row$queries, function(query) {
    list(query=query, total=cannibalize(row$numbers, query))
  })

  # Print the results.
  sapply(1:ncol(results), function(i) {
    result <- results[,i]
    print(paste('Query', result$query, 'Total', result$total, ifelse(result$total == row$answers[i], 'Pass', 'Fail')))
  })
 })
diff --git a/input.R b/input.R
 data <- list(
  list(numbers = c(21, 9, 5, 8, 10, 1, 3), queries = c(10, 15), answers = c(4, 2)),
  list(numbers = c(1, 2, 3, 4, 5), queries = c(5), answers = c(2)),
  list(numbers = c(9, 10, 14, 15, 18, 21, 4, 3, 7, 8, 10, 12), queries = c(9:13), answers = c(9, 9, 8, 7, 6)),
  list(numbers = c(4, 4, 4, 4, 4, 4, 4), queries = c(5), answers = c(0)),
  list(numbers = c(5, 4, 4, 4, 1), queries = c(6), answers = c(1)),
  list(numbers = c(2, 2, 2, 2), queries = c(3), answers = c(0)),
  list(numbers = c(4, 4, 4, 3), queries = c(6), answers = c(1)),
  list(numbers = c(3, 3, 3, 3), queries = c(4), answers = c(0))
 )
diff --git a/output-formatted.txt b/output-formatted.txt
 21, 9, 5, 8, 10, 1, 3, queries = 10, 15, output = 4, 2
 1, 2, 3, 4, 5, queries = 5, output = 2
 9, 10, 14, 15, 18, 21, 4, 3, 7, 8, 10, 12, queries = 9, 10, 11, 12, 13, output = 9, 9, 8, 7, 6
 4, 4, 4, 4, 4, 4, 4, queries = 5, output = 0
 5, 4, 4, 4, 1, queries = 6, output = 1
 2, 2, 2, 2, queries = 3, output = 0
 4, 4, 4, 3, queries = 6, output = 1
 3, 3, 3, 3, queries = 4, output = 0
diff --git a/output-raw.txt b/output-raw.txt
 "Query 10 Total 4 Pass"
 "Query 15 Total 2 Pass"
 "Query 5 Total 2 Pass"
 "Query 9 Total 9 Pass"
 "Query 10 Total 9 Pass"
 "Query 11 Total 8 Pass"
 "Query 12 Total 7 Pass"
 "Query 13 Total 6 Pass"
 "Query 5 Total 0 Pass"
 "Query 6 Total 1 Pass"
 "Query 3 Total 0 Pass"
 "Query 6 Total 1 Pass"
 "Query 4 Total 0 Pass"
	#
	# [2017-10-16] Challenge #336 [Easy] Cannibal numbers
	# https: https://www.reddit.com/r/dailyprogrammer/comments/76qk58/20171016_challenge_336_easy_cannibal_numbers/
	#
	# Demo at http://www.r-fiddle.org/#/fiddle?id=xqqeOaS1&version=2
	#
	# Imagine a given set of numbers wherein some are cannibals.
	# We define a cannibal as a larger number can eat a smaller number and increase its value by 1.
	# There are no restrictions on how many numbers any given number can consume.
	# A number which has been consumed is no longer available.
	# Your task is to determine the number of numbers which can have a value equal to or greater than a specified value.
	#
	# by Kory Becker
	# http://primaryobjects.com
	#

	cannibalize <- function(input, threshold, verbose=F) {
	# Start by counting the numbers that are already >= query.
	count <- length(input[input >= threshold])

	if (verbose) print(paste(count, "number(s) already meet the threshold."))

	# Sort the numbers in descending order.
	numbers <- sort(input[input < threshold], T)
	numbersAsc <- sort(input[input < threshold], F)

	# Use the indices of each number to record consumptions.
	indices <- seq_along(numbers)
	indicesAsc <- rev(indices)

	consumed <- c()

	# For each number, find the smallest numbers to add to make them >= to the query value.
	sapply(indices, function(i) {
	if (!i %in% consumed) {
	number <- numbers[i]

	total <- number

	for (j in indicesAsc) {
	if (!j %in% consumed) {
	n <- numbers[j]

	# A number can't consume itself and must be bigger than the prey.
	if (i != j && total > n) {
	# Consume it.
	total <- total + 1

	if (verbose) print(paste(number, "is trying to consume", n, "for a total of", total))

	# Mark the index as consumed.
	consumed <<- c(consumed, j)

	if (total >= threshold) {
	if (verbose) print('Consumed!')
	count <<- count + 1
	break
	}
	}
	}
	}
	}
	})

	count
	}

	# Our input data.
	data <- list(
	list(numbers = c(21, 9, 5, 8, 10, 1, 3), queries = c(10, 15), answers = c(4, 2)),
	list(numbers = c(1, 2, 3, 4, 5), queries = c(5), answers = c(2)),
	list(numbers = c(9, 10, 14, 15, 18, 21, 4, 3, 7, 8, 10, 12), queries = c(9:13), answers = c(9, 9, 8, 7, 6)),
	list(numbers = c(4, 4, 4, 4, 4, 4, 4), queries = c(5), answers = c(0)),
	list(numbers = c(5, 4, 4, 4, 1), queries = c(6), answers = c(1)),
	list(numbers = c(2, 2, 2, 2), queries = c(3), answers = c(0)),
	list(numbers = c(4, 4, 4, 3), queries = c(6), answers = c(1)),
	list(numbers = c(3, 3, 3, 3), queries = c(4), answers = c(0))
	)

	# Run the canibal numbers method on each problem set.
	x <- sapply(data, function(row) {
	# Get the result for this problem set.
	results <- sapply(row$queries, function(query) {
	list(query=query, total=cannibalize(row$numbers, query))
	})

	# Print the results.
	sapply(1:ncol(results), function(i) {
	result <- results[,i]
	print(paste('Query', result$query, 'Total', result$total, ifelse(result$total == row$answers[i], 'Pass', 'Fail')))
	})
	})
	21, 9, 5, 8, 10, 1, 3, queries = 10, 15, output = 4, 2
	1, 2, 3, 4, 5, queries = 5, output = 2
	9, 10, 14, 15, 18, 21, 4, 3, 7, 8, 10, 12, queries = 9, 10, 11, 12, 13, output = 9, 9, 8, 7, 6
	4, 4, 4, 4, 4, 4, 4, queries = 5, output = 0
	5, 4, 4, 4, 1, queries = 6, output = 1
	2, 2, 2, 2, queries = 3, output = 0
	4, 4, 4, 3, queries = 6, output = 1
	3, 3, 3, 3, queries = 4, output = 0
	"Query 10 Total 4 Pass"
	"Query 15 Total 2 Pass"
	"Query 5 Total 2 Pass"
	"Query 9 Total 9 Pass"
	"Query 10 Total 9 Pass"
	"Query 11 Total 8 Pass"
	"Query 12 Total 7 Pass"
	"Query 13 Total 6 Pass"
	"Query 5 Total 0 Pass"
	"Query 6 Total 1 Pass"
	"Query 3 Total 0 Pass"
	"Query 6 Total 1 Pass"
	"Query 4 Total 0 Pass"