Last active
September 9, 2016 05:59
-
-
Save sujoyu/b4a4c2ddb1890a879a290f004e52472d to your computer and use it in GitHub Desktop.
数字の書いてあるN枚のカードから、足してAになる組み合わせの数をかぞえる
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
object Main { | |
def main(args:Array[String]) = { | |
val sc = new java.util.Scanner(System.in) | |
val n, a = sc.nextInt | |
val x = List.fill(n)(sc.nextInt) | |
val nx = (a :: x).max * n | |
val dpMemo = collection.mutable.ArrayBuffer.fill(n + 1, n + 1, nx + 1)(-1L) | |
def dp(j: Int, k: Int, s: Int): Long = { | |
if (dpMemo(j)(k)(s) >= 0) return dpMemo(j)(k)(s) | |
val xj = x(j - 1) | |
val ret = if (j == 0 && k == 0 && s == 0) 1L | |
else if (j > 0 && s < xj) dp(j - 1, k, s) | |
else if (j > 0 && k > 0 && s >= xj) dp(j - 1, k, s) + dp(j - 1, k - 1, s - xj) | |
else 0L | |
dpMemo(j)(k)(s) = ret | |
ret | |
} | |
val ans = (1 to n).map(k => dp(n, k, k * a)).sum | |
println(ans) | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
http://abc044.contest.atcoder.jp/tasks/arc060_a
こちらのAtCoderの過去問です