Submission #57083

#	Time	Username	Problem	Language	Result	Execution time	Memory
57083		Benq	Divide and conquer (IZhO14_divide)	C++14	100 / 100	142 ms	27932 KiB

divide

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100005;

int N; 
vector<array<int,3>> v;
ll sumG[MX], sumD[MX];

struct {
    map<ll,int> m;
    void ins(ll a, int b) {
        auto it = m.lb(a);
        if (it != m.end() && it->s >= b) return;
        m[a] = b; it = m.find(a);
        while (it != m.begin() && it->s >= prev(it)->s) m.erase(prev(it));
    }
    int query(ll x) {
        auto it = m.lb(x);
        if (it == m.end()) return -1;
        return it->s;
        // for all a >= x what is the max b 
    }
} con;

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N; v.resize(N+1);
    FOR(i,1,N+1) {
        F0R(j,3) cin >> v[i][j];
        sumG[i] = sumG[i-1]+v[i][1];
        sumD[i] = sumD[i-1]+v[i][2];
    }
    ll ans = 0;
    FORd(i,1,N+1) {
        // sumD[j]-v[j][0] >= sumD[i-1]-v[i][0]
        con.ins(sumD[i]-v[i][0],i);
        int t = con.query(sumD[i-1]-v[i][0]);
        ans = max(ans,sumG[t]-sumG[i-1]);
    }
    cout << ans;
}

/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

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