結果
問題 | No.770 Median Sequence |
ユーザー |
|
提出日時 | 2018-12-18 07:49:47 |
言語 | Java (openjdk 23) |
結果 |
AC
|
実行時間 | 1,189 ms / 2,000 ms |
コード長 | 4,938 bytes |
コンパイル時間 | 4,042 ms |
コンパイル使用メモリ | 83,552 KB |
実行使用メモリ | 356,624 KB |
最終ジャッジ日時 | 2024-09-25 07:41:32 |
合計ジャッジ時間 | 15,111 ms |
ジャッジサーバーID (参考情報) |
judge4 / judge5 |
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ファイルパターン | 結果 |
---|---|
other | AC * 20 |
ソースコード
package adv2018;import java.io.ByteArrayInputStream;import java.io.IOException;import java.io.InputStream;import java.io.PrintWriter;import java.util.Arrays;import java.util.InputMismatchException;public class Day18_7 {InputStream is;PrintWriter out;String INPUT = "";void solve(){int mod = 1000000007;long[][] C = new long[4000 + 1][4000 + 1];for (int i = 0; i <= 4000; i++) {C[i][0] = 1;for (int j = 1; j <= i; j++) {C[i][j] = C[i - 1][j - 1] + C[i - 1][j];if (C[i][j] >= mod)C[i][j] -= mod;}}int n = ni()+1;long[][] dp = new long[n][n];for(int i = 0;i < n;i++){dp[0][i] = 1;}// dp[0][2] = 1;long[][] ep = new long[n][n+1];long[][] fp = new long[n][n+1];long[][] gp = new long[n][n+1];for(int i = 0;i < n;i++){if(i < n-1){for(int k = 0;k <= n;k++){fp[i+1][k] += fp[i][k];if(k-1 >= 0)fp[i+1][k-1] += fp[i][k];fp[i+1][k] %= mod;if(k-1 >= 0)fp[i+1][k-1] %= mod;gp[i+1][k] += gp[i][k];}}for(int k = 0;k < n;k++){ep[i][k] += fp[i][k];if(ep[i][k] >= mod)ep[i][k] -= mod;ep[i][k] += gp[i][k];if(ep[i][k] >= mod)ep[i][k] -= mod;}for(int k = 0;k < n;k++){if(k > 0){ep[i][k] += ep[i][k-1];if(ep[i][k] >= mod)ep[i][k] -= mod;}dp[i][k] += ep[i][k];dp[i][k] %= mod;if(dp[i][k] == 0)continue;if(n+i-k >= 0 && n+i-k < n && k+1 <= n){fp[n+i-k][k+1] += dp[i][k];if(fp[n+i-k][k+1] >= mod)fp[n+i-k][k+1] -= mod;}if(i+1 < n){gp[i+1][k+1] += dp[i][k];if(gp[i+1][k+1] >= mod)gp[i+1][k+1] -= mod;}int lim = Math.min(n, n-k+i);if(lim < n){gp[lim][k+1] -= dp[i][k];if(gp[lim][k+1] < 0)gp[lim][k+1] += mod;}// for(int j = i+1;j < n && j <= n-1-k+i;j++){// ep[j][k+1] += dp[i][k];// if(ep[j][k+1] >= mod)ep[j][k+1] -= mod;// }}}out.println(dp[n-1][n-1]);}public static long pow(long a, long n, long mod) {// a %= mod;long ret = 1;int x = 63 - Long.numberOfLeadingZeros(n);for (; x >= 0; x--) {ret = ret * ret % mod;if (n << 63 - x < 0)ret = ret * a % mod;}return ret;}void run() throws Exception{is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());out = new PrintWriter(System.out);long s = System.currentTimeMillis();solve();out.flush();if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");// Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){// @Override// public void run() {// long s = System.currentTimeMillis();// solve();// out.flush();// if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");// }// };// t.start();// t.join();}public static void main(String[] args) throws Exception { new Day18_7().run(); }private byte[] inbuf = new byte[1024];public int lenbuf = 0, ptrbuf = 0;private 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 boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }private double nd() { return Double.parseDouble(ns()); }private char nc() { return (char)skip(); }private String ns(){int b = skip();StringBuilder sb = new StringBuilder();while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')sb.appendCodePoint(b);b = readByte();}return sb.toString();}private 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 int[] na(int n){int[] a = new int[n];for(int i = 0;i < n;i++)a[i] = ni();return a;}private long[] nal(int n){long[] a = new long[n];for(int i = 0;i < n;i++)a[i] = nl();return a;}private 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 int[][] nmi(int n, int m) {int[][] map = new int[n][];for(int i = 0;i < n;i++)map[i] = na(m);return map;}private int ni() { return (int)nl(); }private 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();}}private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }}