Submission #443863

#	Time	Username	Problem	Language	Result	Execution time	Memory
443863		Haruto810198	Global Warming (CEOI18_glo)	C++17	100 / 100	114 ms	14044 KiB

glo

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define double long double

#define FOR(i, l, r, d) for(int i=(l); i<=(r); i+=(d))
#define szof(x) ((int)(x).size())

#define vi vector<int>
#define pii pair<int, int>

#define F first
#define S second

#define pb push_back
#define eb emplace_back
#define mkp make_pair

const int INF = 2147483647;
const int LNF = INF*INF;
const int MOD = 1000000007;
const int mod = 998244353;
const double eps = 1e-12;

const int MAX = 200010;

int n, x;
int arr[MAX][3];
int dp[MAX][3];

vi qu[3];

void modify(int i, int j, int k){

    int pos = dp[i][j] - 1;

    assert(pos <= szof(qu[k]));

    if(pos == szof(qu[k])){
        qu[k].pb(arr[i][j]);
    }
    else{
        qu[k][pos] = min(qu[k][pos], arr[i][j]);
    }

}

int query(int j, int T){

    /// find max{dp[i][j]} s.t. arr[i] < T

    if(qu[j].empty()){
        return 0;
    }

    if(T <= qu[j][0]){
        return 0;
    }

    int L = 0, R = szof(qu[j]) - 1, mid;

    while(L < R){
        mid = (L + R + 1) / 2;
        if(T > qu[j][mid]){
            L = mid;
        }
        else{
            R = mid - 1;
        }
    }

    /// qu[i] : dp = i + 1
    return L + 1;

}

int solve(int d){

    //cerr<<"solve("<<d<<") : "<<endl;

    /// init
    FOR(j, 0, 2, 1){
        qu[j].clear();
    }

    FOR(i, 1, n, 1){
        arr[i][1] = arr[i][0] + d;
    }

    /// dp
    FOR(i, 1, n, 1){

        FOR(j, 0, 2, 1){
            dp[i][j] = query(j, arr[i][j]) + 1;
            //cerr<<"dp["<<i<<"]["<<j<<"] = "<<dp[i][j]<<"\t";
        }
        //cerr<<endl;

        FOR(j, 0, 2, 1){
            FOR(k, 0, j, 1){
                modify(i, k, j);
            }
            /*
            cerr<<"qu["<<j<<"] : ";
            for(int i : qu[j]){
                cerr<<i<<" ";
            }
            cerr<<endl;
            */
        }

    }

    int ret = 0;

    FOR(i, 1, n, 1){
        FOR(j, 0, 2, 1){
            ret = max(ret, dp[i][j]);
        }
    }

    return ret;

}

signed main(){

    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    cin>>n>>x;
    FOR(i, 1, n, 1){
        cin>>arr[i][0];
        arr[i][2] = arr[i][0];
    }

    int res = max(solve(x), solve(-x));

    cout<<res<<'\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