結果

問題 No.770 Median Sequence
ユーザー uwi
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
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ソースコード

diff #
プレゼンテーションモードにする

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)); }
}
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