Submission #1038577

#	Time	Username	Problem	Language	Result	Execution time	Memory
1038577		vjudge1	Global Warming (CEOI18_glo)	C++17	42 / 100	58 ms	7004 KiB

glo

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define ld long double
#define ull unsigned long long
#define pii pair<int,int>
#define pll pair<long long, long long>
#define fi first
#define se second
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define lwb lower_bound
#define upb upper_bound

#define TASKNAME "NAME"

void init()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    ///freopen(TASKNAME".INP","r",stdin); freopen(TASKNAME".OUT","w",stdout);
}

const int maxN = 1e6+5;
const ll INF = INT_MAX / 2, MOD = 1e9+7, INFLL = 2e18;
const double epsilon = 1e-3;

int n, x, a[maxN], b[maxN];
pii lo[maxN], hi[maxN];

int main()
{
    init();
    cin >> n >> x;
    for(int i = 1; i <= n; i++)
    {
        cin >> a[i];
        b[i] = INF;
    }
    b[0] = -INF;
    for(int i = 1; i <= n; i++)
    {
        int pos = lower_bound(b, b + n + 1, a[i]) - b;
        b[pos] = a[i];
        //cout << a[i] << " " << pos << '\n';
        if(pos > lo[i-1].fi)
        {
            lo[i] = {pos, a[i]};
        } else if(pos == lo[i-1].fi && a[i] < lo[i-1].se)
        {
            lo[i].fi = lo[i-1].fi;
            lo[i].se = a[i];
        } else
        {
            lo[i] = lo[i-1];
        }
    }
    for(int i = 1; i <= n; i++)
    {
        b[i] = INF;
    }
    b[0] = -INF;
    for(int i = n; i >= 1; i--)
    {
        int pos = lower_bound(b, b + n + 1, -a[i]) - b;
        b[pos] = -a[i];
        if(pos > hi[i+1].fi)
        {
            hi[i] = {pos, a[i]};
        } else if(pos == hi[i-1].fi && a[i] > hi[i-1].se)
        {
            hi[i].fi = hi[i-1].fi;
            hi[i].se = a[i];
        } else
        {
            hi[i] = hi[i-1];
        }
    }
    int res = lo[n].fi;
    for(int i = 2; i <= n; i++)
    {
        if(abs(lo[i-1].se - hi[i].se) + 1 <= x) res = max(res, lo[i-1].fi + hi[i].fi);
    }
    cout << res;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 13
• Subtask 4: 10 / 10
• Subtask 5: 0 / 20
• Subtask 6: 17 / 17
• Subtask 7: 0 / 25