Submission #692404

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Source Code Expand

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 Main {
	static InputStream is;
	static PrintWriter out;
	static String INPUT = "";
	
	static void solve()
	{
		int n = ni();
		int[] a = na(n);
		if(n == 1){
			out.println(0);
			return;
		}
		OBST2 o = new OBST2(a);
		o.go();
		long w = 0;
		for(int i = n;i < 2*n-1;i++){
			w += o.w[i];
		}
		out.println(w);
	}
	
	public static class OBST2 {
		public int[] w;
		public int[] l, r;
		public int[] d;
		public int[] q;
		public int[] v;
		public int t, m, n;
		
		public OBST2(int[] a)
		{
			n = a.length;
			m = n-1;
			w = new int[2*n-1];
			l = new int[2*n-1];
			r = new int[2*n-1];
			Arrays.fill(l, -1);
			Arrays.fill(r, -1);
			d = new int[2*n-1];
			q = new int[2*n-1];
			v = new int[2*n-1];
			for(int i = 0;i < a.length;i++){
				this.w[i] = a[i];
			}
		}
		
		public void combine(int k)
		{
			m++;
			l[m] = v[k-1]; r[m] = v[k];
			int x = q[k-1] + q[k];
			w[m] = x;
			t--;
			for(int j = k;j <= t;j++){
				q[j] = q[j+1]; v[j] = v[j+1];
			}
			int j;
			for(j = k-2;q[j] < x;j--){
				q[j+1] = q[j]; v[j+1] = v[j];
			}
			q[j+1] = x;
			v[j+1] = m;
			
			while(j > 0 && q[j-1] <= x){
				int dum = t-j;
				combine(j);
				j = t-dum;
			}
		}
		
		void mark(int k, int p)
		{
			d[k] = p;
			if(l[k] >= 0)mark(l[k], p+1);
			if(r[k] >= 0)mark(r[k], p+1);
		}
		
		void build(int b){
			int j = m;
			if(d[t] == b){
				l[j] = t++;
			}else{
				m--;
				l[j] = m;
				build(b+1);
			}
			if(d[t] == b){
				r[j] = t++;
			}else{
				m--;
				r[j] = m;
				build(b+1);
			}
		}
		
		public void go()
		{
			t = 1;
			q[0] = 1000000007;
			q[1] = w[0];
			v[1] = 0;
			for(int k = 1;k <= n-1;k++){
				while(q[t-1] <= w[k])combine(t);
				t++;
				q[t] = w[k];
				v[t] = k;
			}
			while(t > 1)combine(t);
			mark(v[1], 0);
			t = 0;
			m = 2*(n-1);
			build(1);
		}
		
	}
	
	public static void main(String[] args) throws Exception
	{
		long S = System.currentTimeMillis();
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		solve();
		out.flush();
		long G = System.currentTimeMillis();
		tr(G-S+"ms");
	}
	
	private static boolean eof()
	{
		if(lenbuf == -1)return true;
		int lptr = ptrbuf;
		while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;
		
		try {
			is.mark(1000);
			while(true){
				int b = is.read();
				if(b == -1){
					is.reset();
					return true;
				}else if(!isSpaceChar(b)){
					is.reset();
					return false;
				}
			}
		} catch (IOException e) {
			return true;
		}
	}
	
	private static byte[] inbuf = new byte[1024];
	static int lenbuf = 0, ptrbuf = 0;
	
	private static 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 static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
//	private static boolean isSpaceChar(int c) { return !(c >= 32 && c <= 126); }
	private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private static double nd() { return Double.parseDouble(ns()); }
	private static char nc() { return (char)skip(); }
	
	private static String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private static 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 static 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 static int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private static int ni()
	{
		int num = 0, 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 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) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); }
}

Submission Info

Judge Result