Submission #861411
Source Code Expand
import java.io.IOException; import java.io.InputStream; import java.util.NoSuchElementException; public class Main { private static int mod = 1000000000 + 7; public static void main(String[] args) { FastScanner sc = new FastScanner(); int N = sc.nextInt(); int K = sc.nextInt(); if (K == 1) { System.out.println(1); return; } else { int[][] fif = enumFIF(4000005, mod); long[][] dp = new long[N + 1][N + 1]; dp[0][0] = 1L; for (int i = 0; i <= N; i ++) { for (int j = i; j <= N; j ++) { if (i > 0) dp[i][j] += dp[i - 1][j]; if (j > 0) { dp[i][j] += C(i + (K - 1) * j - 1, K - 2, mod, fif) * dp[i][j - 1]; } dp[i][j] %= mod; } } long ans = dp[N][N]; for(long i = 1; i <= N; i ++) { ans = (ans * i) % mod; } System.out.println(ans); } } public static long C(int n, int r, int mod, int[][] fif) { if (n < 0 || r < 0 || r > n) return 0; return (long) fif[0][n] * fif[1][r] % mod * fif[1][n - r] % mod; } public static int[][] enumFIF(int n, int mod) { int[] f = new int[n + 1]; int[] invf = new int[n + 1]; f[0] = 1; for (int i = 1; i <= n; i++) { f[i] = (int) ((long) f[i - 1] * i % mod); } long a = f[n]; long b = mod; long p = 1, q = 0; while (b > 0) { long c = a / b; long d; d = a; a = b; b = d % b; d = p; p = q; q = d - c * q; } invf[n] = (int) (p < 0 ? p + mod : p); for (int i = n - 1; i >= 0; i--) { invf[i] = (int) ((long) invf[i + 1] * (i + 1) % mod); } return new int[][] { f, invf }; } } class FastScanner { public static String debug = null; private final InputStream in = System.in; private int ptr = 0; private int buflen = 0; private byte[] buffer = new byte[1024]; private boolean eos = false; private boolean hasNextByte() { if (ptr < buflen) { return true; } else { ptr = 0; try { if (debug != null) { buflen = debug.length(); buffer = debug.getBytes(); debug = ""; eos = true; } else { buflen = in.read(buffer); } } catch (IOException e) { e.printStackTrace(); } if (buflen < 0) { eos = true; return false; } else if (buflen == 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++; } public boolean isEOS() { return this.eos; } public 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(); } public 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(); } } public int nextInt() { return (int) nextLong(); } public long[] nextLongList(int n) { return nextLongTable(1, n)[0]; } public int[] nextIntList(int n) { return nextIntTable(1, n)[0]; } public long[][] nextLongTable(int n, int m) { long[][] ret = new long[n][m]; for (int i = 0; i < n; i ++) { for (int j = 0; j < m; j ++) { ret[i][j] = nextLong(); } } return ret; } public int[][] nextIntTable(int n, int m) { int[][] ret = new int[n][m]; for (int i = 0; i < n; i ++) { for (int j = 0; j < m; j ++) { ret[i][j] = nextInt(); } } return ret; } }
Submission Info
Submission Time | |
---|---|
Task | F - Leftmost Ball |
User | hiromi_ayase |
Language | Java8 (OpenJDK 1.8.0) |
Score | 1600 |
Code Size | 4253 Byte |
Status | AC |
Exec Time | 743 ms |
Memory | 73880 KB |
Judge Result
Set Name | Sample | All | ||||
---|---|---|---|---|---|---|
Score / Max Score | 0 / 0 | 1600 / 1600 | ||||
Status |
|
|
Set Name | Test Cases |
---|---|
Sample | 0_00.txt, 0_01.txt, 0_02.txt, 0_03.txt |
All | 0_00.txt, 0_01.txt, 0_02.txt, 0_03.txt, 1_00.txt, 1_01.txt, 1_02.txt, 1_03.txt, 1_04.txt, 1_05.txt, 1_06.txt, 1_07.txt, 1_08.txt, 1_09.txt, 1_10.txt, 1_11.txt, 1_12.txt, 1_13.txt, 1_14.txt, 1_15.txt, 1_16.txt, 1_17.txt, 1_18.txt, 1_19.txt |
Case Name | Status | Exec Time | Memory |
---|---|---|---|
0_00.txt | AC | 445 ms | 40020 KB |
0_01.txt | AC | 153 ms | 8020 KB |
0_02.txt | AC | 457 ms | 40020 KB |
0_03.txt | AC | 743 ms | 73756 KB |
1_00.txt | AC | 146 ms | 7888 KB |
1_01.txt | AC | 445 ms | 40020 KB |
1_02.txt | AC | 148 ms | 7760 KB |
1_03.txt | AC | 736 ms | 73752 KB |
1_04.txt | AC | 722 ms | 73760 KB |
1_05.txt | AC | 737 ms | 73760 KB |
1_06.txt | AC | 734 ms | 73828 KB |
1_07.txt | AC | 725 ms | 73760 KB |
1_08.txt | AC | 730 ms | 73880 KB |
1_09.txt | AC | 713 ms | 73748 KB |
1_10.txt | AC | 719 ms | 73752 KB |
1_11.txt | AC | 719 ms | 73764 KB |
1_12.txt | AC | 490 ms | 42444 KB |
1_13.txt | AC | 670 ms | 73756 KB |
1_14.txt | AC | 442 ms | 40020 KB |
1_15.txt | AC | 505 ms | 46332 KB |
1_16.txt | AC | 570 ms | 61584 KB |
1_17.txt | AC | 690 ms | 73828 KB |
1_18.txt | AC | 462 ms | 40532 KB |
1_19.txt | AC | 734 ms | 73752 KB |