コード
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.NoSuchElementException;
public class Main {
private static class Task {
void solve(FastScanner in, PrintWriter out) {
int N = in.nextInt();
String[] pq = in.next().split("/");
double p = Double.parseDouble(pq[0]) / Double.parseDouble(pq[1]);
int[][] A = in.nextIntMap(N, N);
int[] win = new int[N];
for (int i = 0; i < N; i++) for (int j = 0; j < N; j++) win[i] += A[i][j];
int[] leaderBoard = new int[N];
{
ArrayList<int[]> tmp = new ArrayList<>();
for (int i = 0; i < N; i++) {
tmp.add(new int[]{win[i], i});
}
Collections.sort(tmp, (o1, o2) -> o1[0] == o2[0] ? Integer.compare(o1[1], o2[1]) : -Integer.compare(o1[0], o2[0]));
Collections.reverse(tmp);
for (int i = 0; i < N; i++) leaderBoard[i] = tmp.get(i)[1];
}
double[][] dp = new double[N][N + 1];
for (int i = 0; i < N; i++) {
double[] dpi = dp[i];
dpi[0] = 1.0;
for (int j = 0; j < N; j++) {
if (i == j) continue;
double[] next = new double[N + 1];
for (int winNum = 0; winNum < N; winNum++) {
if (A[i][j] == 1) {
next[winNum + 1] += dpi[winNum] * p;
next[winNum] += dpi[winNum] * (1 - p);
}
if (A[i][j] == 0) {
next[winNum + 1] += dpi[winNum] * (1 - p);
next[winNum] += dpi[winNum] * p;
}
}
dpi = next;
}
dp[i] = dpi;
}
double[][] dpWin = new double[N + 1][N + 1];
dpWin[leaderBoard[0]] = dp[leaderBoard[0]];
for (int i = 1; i < N; i++) {
int pre = leaderBoard[i - 1];
int cur = leaderBoard[i];
for (int preWinNum = 0; preWinNum < N; preWinNum++)
for (int curWinNum = preWinNum; curWinNum < N; curWinNum++) {
if (preWinNum == curWinNum && cur > pre) continue;
dpWin[cur][curWinNum] += dpWin[pre][preWinNum] * dp[cur][curWinNum];
}
}
double total = 0.0;
for (int winNum = 0; winNum < N + 1; winNum++) total += dpWin[leaderBoard[N - 1]][winNum];
out.println(total);
}
}
ここから下はテンプレートです。
public static void main(String[] args) {
OutputStream outputStream = System.out;
FastScanner in = new FastScanner();
PrintWriter out = new PrintWriter(outputStream);
Task solver = new Task();
solver.solve(in, out);
out.close();
}
private static class FastScanner {
private final InputStream in = System.in;
private final byte[] buffer = new byte[1024];
private int ptr = 0;
private int bufferLength = 0;
private boolean hasNextByte() {
if (ptr < bufferLength) {
return true;
} else {
ptr = 0;
try {
bufferLength = in.read(buffer);
} catch (IOException e) {
e.printStackTrace();
}
if (bufferLength <= 0) {
return false;
}
}
return true;
}
private int readByte() {
if (hasNextByte()) return buffer[ptr++];
else return -1;
}
private static boolean isPrintableChar(int c) {
return 33 <= c && c <= 126;
}
private void skipUnprintable() {
while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;
}
boolean hasNext() {
skipUnprintable();
return hasNextByte();
}
public String next() {
if (!hasNext()) throw new NoSuchElementException();
StringBuilder sb = new StringBuilder();
int b = readByte();
while (isPrintableChar(b)) {
sb.appendCodePoint(b);
b = readByte();
}
return sb.toString();
}
long nextLong() {
if (!hasNext()) throw new NoSuchElementException();
long n = 0;
boolean minus = false;
int b = readByte();
if (b == '-') {
minus = true;
b = readByte();
}
if (b < '0' || '9' < b) {
throw new NumberFormatException();
}
while (true) {
if ('0' <= b && b <= '9') {
n *= 10;
n += b - '0';
} else if (b == -1 || !isPrintableChar(b)) {
return minus ? -n : n;
} else {
throw new NumberFormatException();
}
b = readByte();
}
}
double nextDouble() {
return Double.parseDouble(next());
}
double[] nextDoubleArray(int n) {
double[] array = new double[n];
for (int i = 0; i < n; i++) {
array[i] = nextDouble();
}
return array;
}
double[][] nextDoubleMap(int n, int m) {
double[][] map = new double[n][];
for (int i = 0; i < n; i++) {
map[i] = nextDoubleArray(m);
}
return map;
}
public int nextInt() {
return (int) nextLong();
}
public int[] nextIntArray(int n) {
int[] array = new int[n];
for (int i = 0; i < n; i++) array[i] = nextInt();
return array;
}
public int[][] nextIntMap(int n, int m) {
int[][] map = new int[n][];
for (int i = 0; i < n; i++) {
map[i] = nextIntArray(m);
}
return map;
}
public long[] nextLongArray(int n) {
long[] array = new long[n];
for (int i = 0; i < n; i++) array[i] = nextLong();
return array;
}
public String[] nextStringArray(int n) {
String[] array = new String[n];
for (int i = 0; i < n; i++) array[i] = next();
return array;
}
public char[][] nextCharMap(int n) {
char[][] array = new char[n][];
for (int i = 0; i < n; i++) array[i] = next().toCharArray();
return array;
}
}
}