Submission #397804

#	Time	Username	Problem	Language	Result	Execution time	Memory
397804		iANikzad	Global Warming (CEOI18_glo)	C++17	100 / 100	78 ms	10052 KiB

glo

#include<bits/stdc++.h>

using namespace std;

#define pb push_back
#define F first
#define S second
#define debug(x) cerr<<#x<<" :"<<x<<"\n"
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define FAST ios_base::sync_with_stdio(false), cin.tie(), cout.tie();
#define int long long

typedef long long ll;
typedef long double ld;

const int maxn = 2e5 + 7;
const int mod = 1e9 + 7;
const int INF = 1e9 + 7;
const int mlog = 20;
const int SQ = 400;

int a[maxn];

int L[maxn], R[maxn];
int dp[maxn], pd[maxn];

int32_t main()
{
    FAST;

    int n, x;
    cin >> n >> x;

    for(int i = 0; i < n; i++)
        cin >> a[i], dp[i] = pd[i] = +INF;

    for(int i = 0; i < n; i++)
    {
        int pos = lower_bound(dp, dp + n, a[i]) - dp;
        L[i] = pos + 1;

        dp[pos] = a[i];
    }

    for(int i = n - 1; i >= 0; i--)
    {
        int pos = lower_bound(pd, pd + n, -a[i] + x) - pd;
        R[i] = pos + 1;

        int npos = lower_bound(pd ,pd + n, -a[i]) - pd;
        pd[npos] = -a[i];
    }

    int ans = 0;
    for(int i = 0; i < n; i++) ans = max(ans, R[i] + L[i] - 1);

    cout << ans << "\n";

    return 0;
}

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