Submission #168642

#	Time	Username	Problem	Language	Result	Execution time	Memory
168642		muhammad_hokimiyon	Divide and conquer (IZhO14_divide)	C++14	100 / 100	233 ms	29236 KiB

divide

#include <bits/stdc++.h>

#pragma GCC optimize("Ofast")

#define fi first
#define se second
#define ll long long

using namespace std;

const int N = 1e5 + 7;
const int mod = 1e9 + 7;

int n;
ll a[N];
ll b[N];
ll d[N];
ll g[N];
ll t[8 * N];
map < ll , int > m;
vector < pair < ll , pair < ll , ll > > > v;

ll get( int x , int l , int r , int tl , int tr )
{
    if( tl > tr )return 1e18;
    if( l == tl && r == tr ){
        return t[x];
    }
    int mid = (l + r) / 2;
    return min( get( x * 2 , l , mid , tl , min(tr , mid) ) ,
               get( x * 2 + 1 , mid + 1 , r , max(tl , mid + 1) , tr ) );
}

void upd( int x , int l , int r , int pos , ll val )
{
    if( l == r ){
        t[x] = min( t[x] , val );
        return;
    }
    int mid = (l + r) / 2;
    if( mid >= pos )upd( x * 2 , l , mid , pos , val );
    else upd( x * 2 + 1 , mid + 1 , r , pos , val );
    t[x] = min( t[x * 2] , t[x * 2 + 1] );
}

void solve()
{
    cin >> n;
    ll ans = 0;
    for( int i = 1; i <= n; i++ ){
        ll x,y,z;
        cin >> x >> y >> z;
        ans = max( ans , y );
        v.push_back({x , {y , z}});
    }
    for( int i = 1; i <= 8 * n; i++ ){
        t[i] = 1e18;
    }
    sort( v.begin() , v.end() );
    vector < ll > o;
    for( int i = 0; i < (int)v.size(); i++ ){
        d[i] = v[i].se.se;
        if( i > 0 )d[i] += d[i - 1] , g[i] = g[i - 1];
        g[i] += v[i].se.fi;
        a[i] = d[i - 1] - v[i].fi;
        b[i] = d[i] - v[i].fi;
        o.push_back(a[i]);
        o.push_back(b[i]);
    }
    int G = 0;
    sort( o.begin() , o.end() );
    for( int i = 0; i < (int)o.size(); i++ ){
        if( m.find(o[i]) == m.end() ){
            m[o[i]] = ++G;
        }
    }
    for( int i = 0; i < (int)v.size(); i++ ){
        ll x = get( 1 , 1 , G , 1 , m[b[i]] );
        //cout << i << " " << x << " " << m[a[i]] << " " << m[b[i]] << " " << g[i] << "\n";
        ans = max( ans , g[i] - x );
        upd( 1 , 1 , G , m[a[i]] , (i > 0 ? g[i - 1] : 0) );
    }
    cout << ans;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    //freopen( "input.txt" , "r" , stdin );
    //freopen( "output.txt" , "w" , stdout );

    int t = 1;//cin >> t;
    while( t-- ){
        solve();
    }
}

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