Submission #719579

#	Time	Username	Problem	Language	Result	Execution time	Memory
719579		vinnipuh01	Stranded Far From Home (BOI22_island)	C++17	20 / 100	1075 ms	58188 KiB

island

#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 = 1000000000000000000;

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, m, a[ 400001 ], x, y;
int an[ 200001 ];
int p[ 400001 ], r[ 400001 ], c[ 400001 ];
int sz[ 400001 ], l[ 400001 ], sf[ 400001 ];

vector <int> v[ 400001 ];
set <pair<int, int> > st;
int used[ 400001 ];
bool ok1 = 1, ok2 = 1;
queue <int> q;

bool bfs( int u ) {
	st.clear();
	st.insert( { 0, u } );
	used[ u ] = 1;
	sum = a[ u ];
	while ( st.size() ) {
		u = st.begin()->second;
		used[ u ] = 1;
		int cost = st.begin()->first;
		st.erase( st.begin() );
		if ( sum < cost )
			return false;
		sum += cost;
		for ( auto to : v[ u ] ) {
			if ( !used[ to ] )
				st.insert( { a[ to ], to } );
		}
	}
	return true;
}

void dfs( int u, int pr = 1, int sum = 0 ) {
	sz[ u ] += a[ u ];
	for ( auto to : v[ u ] ) {
		if ( to != pr ) {
			dfs( to, u, sum );
			sz[ u ] += sz[ to ];
		}
	}
}

main () {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
	cin >> n >> m;
	for ( int i = 1; i <= n; i ++ ) {
		cin >> a[ i ];
		p[ i ] = i;
		r[ i ] = 1;
		c[ i ] = a[ i ];
		st.insert( { a[ i ], i } );
		if ( i > 1 && a[ i ] > a[ i - 1 ] )
			ok1 = 0;
	}
	for ( int i = 1; i <= m; i ++ ) {
		cin >> x >> y;
		v[ x ].push_back( y );
		v[ y ].push_back( x );
		if ( abs( x - y ) != 1 )
			ok2 = 0;
	}
	if ( n <= 2000 ) {
		for ( int i = 1; i <= n; i ++ ) {
			cout << bfs( i );
			for ( int j = 1; j <= n; j ++ )
				used[ j ] = 0;
		}
	}
	else if ( ok1 ) {
		dfs( 1 );
		an[ 1 ] = 1;
		q.push( 1 );
		while ( q.size() ) {
			int u = q.front();
			q.pop();
			for ( auto to : v[ u ] ) {
				if ( sz[ to ] >= a[ u ] && to > u ) {
					an[ to ] = 1;
					q.push( to );
				}
			}
		}
		for ( int i = 1; i <= n; i ++ )
			cout << an[ i ];
		return 0;
	}
	else if ( ok2 ) {
		l[ 1 ] = 0;
		p[ 1 ] = a[ 1 ];
		a[ 0 ] = oo;
		for ( int i = 2; i <= n; i ++ ) {
			p[ i ] = p[ i - 1 ] + a[ i ];
			l[ i ] = i - 1;
			sum = a[ i ];
			while ( a[ l[ i ] ] <= sum ) {
				sum += p[ l[ i ] ] - p[ l[ l[ i ] ] ];
				l[ i ] = l[ l[ i ] ];
			}
		}
		r[ n ] = n + 1;
		sf[ n ] = a[ n ];
		a[ n + 1 ] = oo;
		for ( int i = n - 1; i >= 1; i -- ) {
			sf[ i ] = sf[ i + 1 ] + a[ i ];
			r[ i ] = i - 1;
			sum = a[ i ];
			while ( a[ r[ i ] ] <= sum ) {
				sum += sf[ r[ i ] ] - sf[ r[ r[ i ] ] ];
				r[ i ] = r[ r[ i ] ];
			}
		} 
		
	}
}

Compilation message (stderr)

island.cpp:87:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   87 | main () {
      | ^~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 30
• Subtask 5: 0 / 35