結果
| 問題 |
No.1031 いたずら好きなお姉ちゃん
|
| コンテスト | |
| ユーザー |
 uwi
|
| 提出日時 | 2020-04-18 04:00:54 |
| 言語 | Java (openjdk 23) |
| 結果 |
AC
|
| 実行時間 | 361 ms / 3,500 ms |
| コード長 | 6,621 bytes |
| コンパイル時間 | 4,188 ms |
| コンパイル使用メモリ | 87,812 KB |
| 実行使用メモリ | 91,896 KB |
| 最終ジャッジ日時 | 2024-10-03 22:23:54 |
| 合計ジャッジ時間 | 21,206 ms |
|
ジャッジサーバーID （参考情報） |
judge5 / judge3 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 53 |
ソースコード
package contest200417;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
// O(n)
public class E2 {
InputStream is;
PrintWriter out;
String INPUT = "";
void solve()
{
int n = ni();
int[] a = na(n);
out.println(go(a) + go(rev(a)));
}
public static int[] rev(int[] a){int[] b = new int[a.length];for(int i = 0;i < a.length;i++)b[a.length-1-i] = a[i];return b;}
long go(int[] a)
{
int n = a.length;
int[] larger = enumPrevWall(a);
int[] smaller = enumPrevShutter(a);
int[] par = new int[n+1];
for(int i = 0;i < n;i++){
par[i] = larger[i] == -1 ? n : larger[i];
}
par[n] = -1;
int[][] g = parentToG(par);
int[][] pars = parents3(g, n);
int[] dep = pars[2];
int[][] qs = new int[n][];
long ans = 0;
int p = 0;
for(int i = 0;i < n;i++){
int s = smaller[i];
if(s != -1)qs[p++] = new int[]{i, smaller[i], -1};
ans += dep[i];
}
ans -= n;
lcabatch(g, n, Arrays.copyOf(qs, p));
for(int i = 0;i < p;i++){
ans -= dep[qs[i][2]];
}
return ans;
}
static void lcabatch(int[][] g, int root, int[][] qs)
{
int n = g.length;
int[] ps = new int[n];
for(int[] q : qs){
assert q.length == 3;
ps[q[0]]++;
ps[q[1]]++;
}
int[][][] qg = new int[n][][];
for(int i = 0;i < n;i++)qg[i] = new int[ps[i]][];
for(int[] q : qs){
qg[q[0]][--ps[q[0]]] = q;
qg[q[1]][--ps[q[1]]] = q;
}
lcadfs(root, -1, g, qg, new DJSet(n), new int[n], new boolean[n]);
}
static void lcadfs(int u, int par, int[][] g, int[][][] qg, DJSet ds, int[] anc, boolean[] black)
{
anc[u] = u;
for(int v : g[u]){
if(v == par)continue;
lcadfs(v, u, g, qg, ds, anc, black);
ds.union(u, v);
anc[ds.root(u)] = u;
}
black[u] = true;
for(int[] q : qg[u]){
int v = u^q[0]^q[1];
if(black[v])q[2] = anc[ds.root(v)];
}
}
public static class DJSet {
public int[] upper;
public DJSet(int n) {
upper = new int[n];
Arrays.fill(upper, -1);
}
public int root(int x) {
return upper[x] < 0 ? x : (upper[x] = root(upper[x]));
}
public boolean equiv(int x, int y) {
return root(x) == root(y);
}
public boolean union(int x, int y) {
x = root(x);
y = root(y);
if (x != y) {
if (upper[y] < upper[x]) {
int d = x;
x = y;
y = d;
}
upper[x] += upper[y];
upper[y] = x;
}
return x == y;
}
public int count() {
int ct = 0;
for (int u : upper)
if (u < 0)
ct++;
return ct;
}
}
public static int[][] parents3(int[][] g, int root) {
int n = g.length;
int[] par = new int[n];
Arrays.fill(par, -1);
int[] depth = new int[n];
depth[0] = 0;
int[] q = new int[n];
q[0] = root;
for (int p = 0, r = 1; p < r; p++) {
int cur = q[p];
for (int nex : g[cur]) {
if (par[cur] != nex) {
q[r++] = nex;
par[nex] = cur;
depth[nex] = depth[cur] + 1;
}
}
}
return new int[][] { par, q, depth };
}
public static int[][] parentToG(int[] par)
{
int n = par.length;
int[] ct = new int[n];
for(int i = 0;i < n;i++){
if(par[i] >= 0){
ct[i]++;
ct[par[i]]++;
}
}
int[][] g = new int[n][];
for(int i = 0;i < n;i++){
g[i] = new int[ct[i]];
}
for(int i = 0;i < n;i++){
if(par[i] >= 0){
g[par[i]][--ct[par[i]]] = i;
g[i][--ct[i]] = par[i];
}
}
return g;
}
public static int[] enumPrevWall(int[] a)
{
int n = a.length;
int[] L = new int[n];
L[0] = -1;
for(int i = 1;i < n;i++){
L[i] = i-1;
while(L[i] >= 0 && a[L[i]] < a[i])L[i] = L[L[i]];
}
return L;
}
public static int[] enumPrevShutter(int[] a)
{
int n = a.length;
int[] L = new int[n];
L[0] = -1;
for(int i = 1;i < n;i++){
L[i] = i-1;
while(L[i] >= 0 && a[L[i]] > a[i])L[i] = L[L[i]];
}
return L;
}
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 E2().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)); }
}