Submission #824277

#	Time	Username	Problem	Language	Result	Execution time	Memory
824277		Dec0Dedd	Global Warming (CEOI18_glo)	C++14	0 / 100	245 ms	29172 KiB

glo

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

#pragma GCC optimize("Ofast")
 
const int N = 2e5+10;
const int INF = 1e9+10;
 
struct segtree {
    vector<int> t;
    int sz;
 
    void init(int k) {
        sz=k+1;
        t.resize(2*sz);
    }

    void upd(int p, int val) {
        t[p+sz]=max(t[p+sz], val);
        for (; p>1; p>>=1) t[p>>1]=max(t[p], t[p^1]);
    }

    int que(int l, int r) {
        int res=0;
        for (l+=sz, r+=sz; l<r; l>>=1, r>>=1) {
            if (l&1) res=max(res, t[l++]);
            if (r&1) res=max(res, t[--r]);
        } return res;
    }
};
 
int a[N], n, x, pre[N], suf[N];
unordered_map<int, int> sc;

int lis() {
    vector<int> dp(n+1, INF);
    dp[0]=-INF;

    for (int i=1; i<=n; ++i) {
        int l=upper_bound(dp.begin(), dp.end(), a[i])-dp.begin();
        if (dp[l-1] < a[i] && a[i] < dp[l]) dp[l]=a[i];
    }

    int res=0;
    for (int i=1; i<=n; ++i) {
        if (dp[i] < INF) res=i;
    } return res;
}
 
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    
    cin>>n>>x;
 
    set<int> st;
    for (int i=1; i<=n; ++i) {
        cin>>a[i];
        st.insert(a[i]), st.insert(a[i]+x);
    }
 
    int i=1;
    for (auto u : st) sc[u]=i++;
 
    segtree tr2; tr2.init(2*n+10);
    for (int i=n; i>=1; --i) {
        suf[i]=tr2.que(sc[a[i]]+1, 2*n+1)+1;
        tr2.upd(sc[a[i]], suf[i]);
    }
 
    /*
    cout<<"pre: ";
    for (int i=1; i<=n; ++i) cout<<pre[i]<<" ";
    cout<<"\n";
 
    cout<<"suf: ";
    for (int i=1; i<=n; ++i) cout<<suf[i]<<" ";
    cout<<"\n";
    */
 
    int ans=0;
    segtree tr; tr.init(2*n+1);
    for (int i=1; i+1<=n; ++i) {
        pre[i]=tr.que(1, sc[a[i]])+1;
        tr.upd(sc[a[i]], pre[i]);
        ans=max(ans, tr.que(1, sc[a[i+1]+x])+suf[i+1]);
    } cout<<ans<<"\n";
}

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