제출 #1223398

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1223398		12345678	여별 열쇠 (JOI15_keys)	C++20	100 / 100	1 ms	2380 KiB

keys

#include <bits/stdc++.h>

using namespace std;

const int nx=2e3+5;

int n, m, k, res, l[nx], r[nx], nxt[2*nx], vs[2*nx], dp[2*nx][nx][2];
vector<pair<int, int>> v={{0, 0}};
vector<int> s;

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>m>>k;
    for (int i=1; i<=n; i++) cin>>l[i]>>r[i], s.push_back(l[i]), s.push_back(r[i]);
    s.push_back(0);
    s.push_back(m);
    sort(s.begin(), s.end());
    for (int i=1; i<=n; i++)
    {
        auto idx=lower_bound(s.begin(), s.end(), l[i])-s.begin();
        nxt[idx]=lower_bound(s.begin(), s.end(), r[i])-s.begin()-1;
    }
    //for (int i=0; i<s.size(); i++) cout<<"nxt "<<i<<' '<<nxt[i]<<'\n';
    for (int i=0; i<s.size()-1; i++)
    {
        if (vs[i]) continue;
        if (nxt[i]==0) res+=s[i+1]-s[i];
        else
        {
            if (nxt[i]==i) v.push_back({s[i+1]-s[i], 1}), v.push_back({0, 0});
            else
            {
                int cur=i;
                while (nxt[cur])
                {
                    vs[cur]=1;
                    v.push_back({s[cur+1]-s[cur], 1});
                    cur=nxt[cur];
                }
                vs[cur]=1;
                v.push_back({s[cur+1]-s[cur], 0});
            }
        }
    }
    //cout<<"res "<<res<<'\n';
    for (int i=1; i<v.size(); i++)
    {
        //cout<<"item "<<v[i].first<<' '<<v[i].second<<'\n';
        if (v[i].second) dp[i][0][0]=-1e9;
        else dp[i][0][0]=0;
        for (int j=1; j<=k; j++)
        {
            dp[i][j][0]=max(dp[i-1][j-v[i].second][0]+v[i].first, dp[i-1][j-v[i].second][1]);
            dp[i][j][1]=max(dp[i-1][j][0], dp[i-1][j][1]);
            //cout<<"debug dp "<<i<<' '<<j<<' '<<dp[i][j][0]<<' '<<dp[i][j][1]<<'\n';
        }
    }
    cout<<res+dp[v.size()-1][k][0]<<'\n';
}

/*
2 20 1
4 10
8 15
*/

• Subtask 1: 10 / 10
• Subtask 2: 90 / 90