Submission #1040421

#	Time	Username	Problem	Language	Result	Execution time	Memory
1040421		vjudge1	Divide and conquer (IZhO14_divide)	C++14	100 / 100	44 ms	7996 KiB

divide

#include<bits/stdc++.h>
using namespace std ; 
#define maxn 200009
#define ll long long 
#define pb push_back 
#define fi first 
#define se second 
#define left id<<1
#define right id<<1|1 
#define re exit(0); 
#define _lower(x) lower_bound(v.begin(),v.end(),x)-v.begin()+1
const int mod = 1e9+7 ;
const int INF = 1e9 ; 

typedef vector<int> vi ; 
typedef pair<int,int> pii ; 
typedef vector<pii> vii ; 

template < typename T > void chkmin ( T &a , T b ) { if ( a > b ) a = b ; } 
template < typename T > void chkmax ( T &a , T b ) { if ( a < b ) a = b ; } 

void add ( int &a , int b ) 
{
	a += b ; 
	if ( a >= mod ) a -= mod ; 
	if ( a < 0 ) a += mod ; 
}

void rf () 
{
	freopen ("bai1.inp","r",stdin) ;
}

int _pow ( int a , int n ) 
{
	if ( n == 0 ) return 1 ; 
	int res = _pow (a,n/2) ; 
	if ( n % 2 ) return 1ll*res*res%mod*a%mod ; 
	else return 1ll*res*res%mod ; 
}

int n ; 
int x [maxn] , g [maxn] , e [maxn] ; 
ll sume [maxn] , sumg [maxn] ; 

vector<ll> v ; 
void mapping () 
{
	for ( int i = 1 ; i <= n ; i ++ ) 
	{
		v . pb (sume[i]-x[i]) , v . pb (sume[i-1]-x[i]) ; 
	}
	sort (v.begin(),v.end()) ; 
	v.resize(unique(v.begin(),v.end())-v.begin()) ; 
}

ll bit [maxn] ; 
void update ( int x , ll w )
{
	while ( x < maxn ) chkmin (bit[x],w) , x += (x&-x) ; 
}
ll get ( int x ) 
{
	ll res = 1e18 ; 
	while ( x ) chkmin (res,bit[x]) , x -= (x&-x) ;
	return res ; 
}
int main () 
{
	ios_base::sync_with_stdio(0); 
	cin.tie(0);cout.tie(0); 
//	rf () ; 	
	cin >> n ; 
	for ( int i = 1 ; i <= n ; i ++ ) cin >> x [i] >> g [i] >> e [i] ; 
	for ( int i = 1 ; i <= n ; i ++ ) sumg [i] = sumg [i-1] + g [i] , sume [i] = sume [i-1] + e [i] ; 
	
	mapping () ; 
	
	ll res = 0 ; 
	memset (bit,0x3f,sizeof bit) ; 
	for ( int i = 1 ; i <= n ; i ++ ) 
	{
		update (_lower(sume[i-1]-x[i]),sumg[i-1]) ; 
		chkmax (res,sumg[i]-get(_lower(sume[i]-x[i]))) ; 
	}
	cout << res ; 
}

Compilation message (stderr)

divide.cpp: In function 'void rf()':
divide.cpp:31:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |  freopen ("bai1.inp","r",stdin) ;
      |  ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 17 / 17
• Subtask 2: 31 / 31
• Subtask 3: 52 / 52