Submission #1125812

#	Time	Username	Problem	Language	Result	Execution time	Memory
1125812		vladilius	Global Warming (CEOI18_glo)	C++20	28 / 100	2095 ms	8752 KiB

glo

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second

struct ST{
    vector<int> t;
    int n;
    ST(int ns){
        n = ns;
        t.resize(4 * n);
    }
    void upd(int v, int tl, int tr, int& p, int& x){
        if (tl == tr){
            t[v] = max(t[v], x);
            return;
        }
        int tm = (tl + tr) / 2, vv = 2 * v;
        if (p <= tm){
            upd(vv, tl, tm, p, x);
        }
        else {
            upd(vv + 1, tm + 1, tr, p, x);
        }
        t[v] = max(t[vv], t[vv + 1]);
    }
    void upd(int p, int x){
        upd(1, 1, n, p, x);
    }
    int get(int v, int tl, int tr, int& l, int& r){
        if (l > tr || r < tl) return 0;
        if (l <= tl && tr <= r) return t[v];
        int tm = (tl + tr) / 2, vv = 2 * v;
        return max(get(vv, tl, tm, l, r), get(vv + 1, tm + 1, tr, l, r));
    }
    int get(int l, int r){
        if (l > r) return 0;
        return get(1, 1, n, l, r);
    }
    void clear(){
        fill(t.begin(), t.end(), 0);
    }
};

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int n, X; cin>>n>>X;
    vector<int> a(n + 1);
    for (int i = 1; i <= n; i++){
        cin>>a[i];
    }
    
    auto lis = [&](vector<int> x){
        vector<pii> all;
        for (int i = 1; i <= n; i++){
            all.pb({x[i], i});
        }
        sort(all.begin(), all.end());
        int i = 0, cc = 1;
        while (i < n){
            int j = i;
            while (j < n && all[i].ff == all[j].ff){
                x[all[j].ss] = cc;
                j++;
            }
            i = j; cc++;
        }
        
        ST T(n);
        vector<int> dp(n + 1);
        int ret = 0;
        for (int i = 1; i <= n; i++){
            dp[i] = 1 + T.get(1, x[i] - 1);
            ret = max(ret, dp[i]);
            T.upd(x[i], dp[i]);
        }
        
        return ret;
    };
    
    
    // LIS(a1, a2, ..., ai, a[i + 1] + X, ..., an + X)
    
    int out = lis(a);
    
    for (int i = 1; i <= n; i++){
        a[i] -= X;
        out = max(out, lis(a));
    }
    
    for (int i = 1; i <= n; i++) a[i] += X;
    
    vector<int> all;
    for (int i = 1; i <= n; i++){
        all.pb(a[i]);
    }
    sort(all.begin(), all.end());
    
    vector<int> vv = {0};
    int i = 0;
    while (i < n){
        int j = i;
        while (j < n && all[i] == all[j]){
            j++;
        }
        vv.pb(all[i]);
        i = j;
    }
    
    vector<int> :: iterator it;
    
    vector<int> D2(n + 1);
    ST T(n);
    for (int i = n; i > 0; i--){
        it = lower_bound(vv.begin(), vv.end(), a[i]);
        int j = (int) (it - vv.begin());
        
        D2[i] = 1 + T.get(j + 1, n);
        T.upd(j, D2[i]);
    }
    
    vector<int> dp2(n + 1);
    T.clear();
    for (int i = 1; i <= n; i++){
        it = lower_bound(vv.begin(), vv.end(), a[i] + X);
        int j = (int) (it - vv.begin());

        out = max(out, T.get(1, j - 1) + D2[i]);
        
        it = lower_bound(vv.begin(), vv.end(), a[i]);
        j = (int) (it - vv.begin());
        
        dp2[i] = 1 + T.get(1, j - 1);
        T.upd(j, dp2[i]);
    }

    cout<<out<<"\n";
}

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