Submission #718045

#	Time	Username	Problem	Language	Result	Execution time	Memory
718045		vinnipuh01	Group Photo (JOI21_ho_t3)	C++17	64 / 100	4150 ms	67672 KiB

Main

#include <iostream>
#include <bits/stdc++.h>
#include <cmath>
#include <algorithm>
#include <vector>
#include <deque>
#include <set>
#include <stack>
#include <string>
#include <map>
#include <queue>
//#define int long long
#define sqrt sqrtl

using namespace std;

const long long oo = 1e9;

long long sum, ans = 0, mx = 0, mn = 1000000000, num, pos;


/*
    ViHHiPuh

   (( `'-""``""-'` ))
     )-__-_.._-__-(
   / --- (o _ o) --- \
   \ .-* ( .0. ) *-. /
   _'-. ,_ '=' _, .-'_
  / `;#'#'# - #'#'#;` \
 \_)) -----'#'----- ((_/
      # --------- #
  '# ------- ------ #'
  /..-'# ------- #'-.\
  _\...-\'# -- #'/-.../_
  ((____)- '#' -(____))


    cout << fixed << setprecision(6) << x;


    freopen ( "sum.in", "r", stdin )
*/

int n, a[ 5001 ], t[ 20001 ], tt[ 20001 ], b[ 5001 ];
int dp[ 5001 ], d[ 5001 ][ 5001 ];

void build( int v, int tl, int tr ) {
	if ( tl == tr ) {
		t[ v ] = 1;
		return;
	}
	int mid = ( tl + tr ) / 2;
	build( v + v, tl, mid );
	build( v + v + 1, mid + 1, tr );
	t[ v ] = t[ v + v ] + t[ v + v + 1 ];
}

void build1( int v, int tl, int tr ) {
	tt[ v ] = 0;
	if ( tl == tr ) {
		return;
	}
	int mid = ( tl + tr ) / 2;
	build1( v + v, tl, mid );
	build1( v + v + 1, mid + 1, tr );
}

void upd( int v, int tl, int tr, int pos ) {
	if ( tl > pos || tr < pos )
		return;
	if ( tl == tr ) {
		t[ v ] = 0;
		tt[ v ] = 1;
		return;
	}
	int mid = ( tl + tr ) / 2;
	upd( v + v, tl, mid, pos );
	upd( v + v + 1, mid + 1, tr, pos );
	t[ v ] = t[ v + v ] + t[ v + v + 1 ];
	tt[ v ] = tt[ v + v ] + tt[ v + v + 1 ];
}

void upd1( int v, int tl, int tr, int pos ) {
	if ( tl > pos || tr < pos )
		return;
	if ( tl == tr ) {
		tt[ v ] = 1;
		return;
	}
	int mid = ( tl + tr ) / 2;
	upd1( v + v, tl, mid, pos );
	upd1( v + v + 1, mid + 1, tr, pos );
	tt[ v ] = tt[ v + v ] + tt[ v + v + 1 ];
}

void gett( int v, int tl, int tr, int l, int r ) {
	if ( tl > r || tr < l )
		return;
	if ( tl >= l && tr <= r ) {
		num += t[ v ];
		sum += tt[ v ];
		return;
	}
	int mid = ( tl + tr ) / 2;
	gett( v + v, tl, mid, l, r );
	gett( v + v + 1, mid + 1, tr, l, r );
}

main () {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
	cin >> n;
	for ( int i = 1; i <= n; i ++ ) {
		cin >> a[ i ];
		b[ a[ i ] ] = i;
		dp[ i ] = oo;
	}
	build( 1, 1, n );
	for ( int i = 1; i <= n; i ++ ) {
		build1( 1, 1, n );
		for ( int j = i; j >= 1; j -- ) {
			d[ j ][ i ] = d[ j + 1 ][ i ];
			upd( 1, 1, n, b[ j ] );
			num = 0;
			gett( 1, 1, n, 1, b[ j ] );
			d[ j ][ i ] += num;
			sum = 0;
			if ( b[ j ] < n )
				gett( 1, 1, n, b[ j ] + 1, n );
			d[ j ][ i ] += sum;
//			cout << j << " " << i << " - " << d[ j ][ i ] << "\n";
		}
	}
	for ( int i = 1; i <= n; i ++ ) {
		for ( int j = i - 1; j >= 0; j -- ) {
			dp[ i ] = min( dp[ i ], dp[ j ] + d[ j + 1 ][ i ] );
		}
	}
	cout << dp[ n ];
}

/*

h[ i ] + i * 2 < h[ i + 1 ] + i * 2 + 4

h[ i ] - h[ i + 1 ] < 4

3 5 2 4 1
5 9 8 14 13

*/

Compilation message (stderr)

Main.cpp:110:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  110 | main () {
      | ^~~~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 32 / 32
• Subtask 4: 20 / 20
• Subtask 5: 0 / 36