Submission #1173370

#	Time	Username	Problem	Language	Result	Execution time	Memory
1173370		iamhereforfun	Divide and conquer (IZhO14_divide)	C++20	100 / 100	45 ms	6648 KiB

divide

// IamHereForFun //

#include <bits/stdc++.h>

using namespace std;

#define LSOne(S) ((S) & -(S))

const int N = 1e5 + 5;
const int Q = 2e5 + 5;
const int M = 1e6 + 5;
const int LG = 18;
const int P = 31;
const long long INF = 4e18;
const int MOD = 1e9;

class Fenwick
{
    private:
    vector<long long> ft;
    int n;
    public:
    Fenwick(int len)
    {
        n = len;
        ft.assign(n + 1, INF);
    }
    void updFt(int pos, long long val)
    {
        while(pos <= n)
        {
            ft[pos] = min(ft[pos], val);
            pos += LSOne(pos);
        }
    }
    long long getMin(int pos)
    {
        long long ans = INF;
        while(pos > 0)
        {
            ans = min(ans, ft[pos]);
            pos -= LSOne(pos);
        }
        return ans;
    }
};

int n;
long long pref[N], ans = 0;
array<long long, 3> mine[N];
vector<long long> vec;

int getIdx(long long a)
{
    return lower_bound(vec.begin(), vec.end(), a) - vec.begin() + 1;
}

void prtSolve()
{
    cin >> n;
    for (int x = 0; x < n; x++)
    {
        cin >> mine[x][0] >> mine[x][1] >> mine[x][2];
        if(mine[x][2] >= 1) ans = max(ans, mine[x][1]);
    }
    sort(mine, mine + n);
    pref[0] = mine[0][2];
    for (int x = 1; x < n; x++)
    {
        pref[x] = pref[x - 1] + mine[x][2];
    }
    for(int x = 0; x < n - 1; x++) 
    {
        vec.push_back(pref[x] - mine[x + 1][0]);
        vec.push_back(pref[x + 1] - mine[x + 1][0]);
        // cout << vec.back() << "\n";
    }
    vec.push_back(mine[0][0]);
    sort(vec.begin(), vec.end());
    vec.erase(unique(vec.begin(), vec.end()), vec.end());
    Fenwick ft(vec.size());
    long long sum = 0;
    ft.updFt(getIdx(mine[0][0]), 0);
    sum = mine[0][1];
    for(int x = 0; x < n - 1; x++)
    {
        sum += mine[x + 1][1];
        // cout << sum << " " << ft.getMin(getIdx(pref[x + 1] - mine[x + 1][0])) << " " << pref[x] - mine[x + 1][0] << "\n";
        ans = max(ans, sum - ft.getMin(getIdx(pref[x + 1] - mine[x + 1][0])));
        ft.updFt(getIdx(pref[x] - mine[x + 1][0]), sum - mine[x + 1][1]);
    }
    cout << ans;
}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t = 1;
    // cin >> t;
    for (int x = 1; x <= t; x++)
    {
        prtSolve();
    }
    return 0;
}

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