結果
| 問題 |
No.108 トリプルカードコンプ
|
| コンテスト | |
| ユーザー |
 narushima
|
| 提出日時 | 2020-04-09 20:33:21 |
| 言語 | Java (openjdk 23) |
| 結果 |
AC
|
| 実行時間 | 109 ms / 5,000 ms |
| コード長 | 6,836 bytes |
| コンパイル時間 | 2,956 ms |
| コンパイル使用メモリ | 86,988 KB |
| 実行使用メモリ | 54,204 KB |
| 最終ジャッジ日時 | 2024-09-13 20:20:02 |
| 合計ジャッジ時間 | 5,606 ms |
|
ジャッジサーバーID （参考情報） |
judge1 / judge2 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 20 |
ソースコード
import java.io.*;
import java.util.*;
public class Main {
static InputStream is;
static PrintWriter out;
static String INPUT = "";
static final long mod = (long) 1e9 + 7;
static final int dx[] = { -1, 0, 1, 0 }, dy[] = { 0, -1, 0, 1 };
static final int[] dx8 = { -1, -1, -1, 0, 0, 1, 1, 1 }, dy8 = { -1, 0, 1, -1, 1, -1, 0, 1 };
static final int inf = Integer.MAX_VALUE / 3;
static final long linf = Long.MAX_VALUE / 3;
static final double dinf = Double.MAX_VALUE / 3;
static int n, a[];
static double dp[][][];
static void solve() {
n = ni();
a = na(n);
dp = new double[n+1][n+1][n+1];
for(int i=0;i<n+1;i++)for(int j=0;j<n+1;j++)for(int k=0;k<n+1;k++)dp[i][j][k] = -1;
int s[] = new int[3];
for(int i=0;i<n;i++) {
if(a[i]==0)continue;
if(a[i]>=3)s[2]++;
else s[a[i]-1]++;
}
dp[0][0][n] = 0;//全部３枚
double ans = rec(s[0], s[1], s[2]);
out.println(ans);
}
static double rec(int i, int j, int k) {
if(dp[i][j][k] != -1)return dp[i][j][k];
double p = ((double)n - k)/n; //次に遷移する確率
double e = 1 / p;
if(i+j+k<n)e += ((double) n - (i + j + k)) / (n * p) * rec(i+1, j, k);
if(i-1>=0&&j+1<n+1)e += (double)i / (n * p) * rec(i-1, j+1, k);
if(j-1>=0&&k+1<n+1)e += (double)j / (n * p) * rec(i, j-1, k+1);
return dp[i][j][k] = e;
}
//libraries
static int[] concat(int x, int arr[]) {
int ret[] = new int[arr.length + 1];
System.arraycopy(arr, 0, ret, 1, ret.length - 1);
ret[0] = x;
return ret;
}
static int[] concat(int arr[], int x) {
int ret[] = new int[arr.length + 1];
System.arraycopy(arr, 0, ret, 0, ret.length - 1);
ret[ret.length - 1] = x;
return ret;
}
static long[] concat(long x, long arr[]) {
long ret[] = new long[arr.length + 1];
System.arraycopy(arr, 0, ret, 1, ret.length - 1);
ret[0] = x;
return ret;
}
static long[] concat(long arr[], long x) {
long ret[] = new long[arr.length + 1];
System.arraycopy(arr, 0, ret, 0, ret.length - 1);
ret[ret.length - 1] = x;
return ret;
}
static long max(long x, long y) {
return Math.max(x, y);
}
static long min(long x, long y) {
return Math.min(x, y);
}
static long max(long x, long y, long z) {
x = Math.max(x, y);
x = Math.max(x, z);
return x;
}
static long min(long x, long y, long z) {
x = Math.min(x, y);
x = Math.min(x, z);
return x;
}
static double max(double x, double y) {
return Math.max(x, y);
}
static double min(double x, double y) {
return Math.min(x, y);
}
static double max(double x, double y, double z) {
x = Math.max(x, y);
x = Math.max(x, z);
return x;
}
static double min(double x, double y, double z) {
x = Math.min(x, y);
x = Math.min(x, z);
return x;
}
static void rsort(int[] ar) {
Arrays.sort(ar);
int len = ar.length;
for (int i = 0; i < len / 2; i++) {
int tmp = ar[i];
ar[i] = ar[len - 1 - i];
ar[len - 1 - i] = tmp;
}
}
static void rsort(long[] ar) {
Arrays.sort(ar);
int len = ar.length;
for (int i = 0; i < len / 2; i++) {
long tmp = ar[i];
ar[i] = ar[len - 1 - i];
ar[len - 1 - i] = tmp;
}
}
static void rsort(double[] ar) {
Arrays.sort(ar);
int len = ar.length;
for (int i = 0; i < len / 2; i++) {
double tmp = ar[i];
ar[i] = ar[len - 1 - i];
ar[len - 1 - i] = tmp;
}
}
static void fill(int arr[], int x) {
Arrays.fill(arr, x);
}
static void fill(long arr[], long x) {
Arrays.fill(arr, x);
}
static void fill(double arr[], double x) {
Arrays.fill(arr, x);
}
static void fill(int arr[][], int x) {
for (int i = 0; i < arr.length; i++)
Arrays.fill(arr[i], x);
}
static void fill(long arr[][], long x) {
for (int i = 0; i < arr.length; i++)
Arrays.fill(arr[i], x);
}
static void fill(double arr[][], double x) {
for (int i = 0; i < arr.length; i++)
Arrays.fill(arr[i], x);
}
//MOD culc
static long plus(long x, long y) {
long res = (x + y) % mod;
return res < 0 ? res + mod : res;
}
static long sub(long x, long y) {
long res = (x - y) % mod;
return res < 0 ? res + mod : res;
}
static long mul(long x, long y) {
long res = (x * y) % mod;
return res < 0 ? res + mod : res;
}
static long div(long x, long y) {
long res = x * pow(y, mod - 2) % mod;
return res < 0 ? res + mod : res;
}
static long pow(long x, long y) {
if (y < 0)
return 0;
if (y == 0)
return 1;
if (y % 2 == 1)
return (x * pow(x, y - 1)) % mod;
long root = pow(x, y / 2);
return root * root % mod;
}
public static void main(String[] args) throws Exception {
is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
out = new PrintWriter(System.out);
solve();
out.flush();
}
//input
private static byte[] inbuf = new byte[1024];
static int lenbuf = 0, ptrbuf = 0;
private static int readByte() {
if (lenbuf == -1)
throw new InputMismatchException();
if (ptrbuf >= lenbuf) {
ptrbuf = 0;
try {
lenbuf = is.read(inbuf);
} catch (IOException e) {
throw new InputMismatchException();
}
if (lenbuf <= 0)
return -1;
}
return inbuf[ptrbuf++];
}
private static boolean isSpaceChar(int c) {
return !(c >= 33 && c <= 126);
}
private static int skip() {
int b;
while ((b = readByte()) != -1 && isSpaceChar(b))
;
return b;
}
private static double nd() {
return Double.parseDouble(ns());
}
private static char nc() {
return (char) skip();
}
private static String ns() {
int b = skip();
StringBuilder sb = new StringBuilder();
while (!(isSpaceChar(b))) {
sb.appendCodePoint(b);
b = readByte();
}
return sb.toString();
}
private static char[] ns(int n) {
char[] buf = new char[n];
int b = skip(), p = 0;
while (p < n && !(isSpaceChar(b))) {
buf[p++] = (char) b;
b = readByte();
}
return n == p ? buf : Arrays.copyOf(buf, p);
}
private static char[][] nm(int n, int m) {
char[][] map = new char[n][];
for (int i = 0; i < n; i++)
map[i] = ns(m);
return map;
}
private static int[] na(int n) {
int[] a = new int[n];
for (int i = 0; i < n; i++)
a[i] = ni();
return a;
}
private static int ni() {
int num = 0, b;
boolean minus = false;
while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
;
if (b == '-') {
minus = true;
b = readByte();
}
while (true) {
if (b >= '0' && b <= '9') {
num = num * 10 + (b - '0');
} else {
return minus ? -num : num;
}
b = readByte();
}
}
private static long nl() {
long num = 0;
int b;
boolean minus = false;
while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
;
if (b == '-') {
minus = true;
b = readByte();
}
while (true) {
if (b >= '0' && b <= '9') {
num = num * 10 + (b - '0');
} else {
return minus ? -num : num;
}
b = readByte();
}
}
}