ABC088B - Card Game for Two

問題

https://atcoder.jp/contests/abs/tasks/abc088_b

1回目

回答

N = gets.to_i
A = gets.split.map &:to_i
 
for i in 0..N-2 do
  for j in 0..N-2-i do
    if A[j] < A[j+1] 
      hoji = A[j]
      A[j] = A[j+1]
      A[j+1] = hoji
    end
  end
end
 
i = 0
aliceSum = 0
bobSum = 0
while i < N
  aliceSum += A[i]
  if i+1 < N
    bobSum += A[i+1]
  end
  i += 2
end
 
puts aliceSum - bobSum

結果

2回目

回答

N = gets.to_i
A = gets.split.map(&:to_i).sort.reverse

result = 0

for i in 0..N-1
  if i % 2 == 0
    result += A[i]
  else
    result -= A[i]
  end
end

puts result

結果

感想

sortあるんか〜〜〜〜〜い