Submission #1025931

#	Time	Username	Problem	Language	Result	Execution time	Memory
1025931		ttamx	The short shank; Redemption (BOI21_prison)	C++17	100 / 100	375 ms	268704 KiB

prison

#include<bits/stdc++.h>

using namespace std;

const int INF=INT_MAX/2;

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    int n,d,t;
    cin >> n >> d >> t;
    vector<int> a(n);
    for(auto &x:a)cin >> x;
    vector<int> pre(n,-1);
    stack<pair<int,int>> s;
    s.emplace(-INF,-1);
    int ans=0;
    for(int i=0;i<n;i++){
        int x=min(a[i],t)-i;
        while(s.top().first>x)s.pop();
        if(a[i]>t)pre[i]=s.top().second;
        else ans++;
        s.emplace(a[i]-i,i);
    }
    vector<pair<int,int>> range;
    for(int i=0;i<n;i++)if(pre[i]!=-1)range.emplace_back(pre[i],i-1);
    int m=range.size();
    ans+=m;
    vector<vector<int>> g(m);
    vector<int> par(m,-1);
    stack<pair<int,int>> st;
    for(int i=0;i<m;i++){
        int x=range[i].first;
        while(!st.empty()&&st.top().first>=x){
            int j=st.top().second;
            st.pop();
            g[i].emplace_back(j);
            par[j]=i;
        }
        st.emplace(x,i);
    }
    vector<int> b;
    function<int(int)> dfs=[&](int u){
        vector<int> dep;
        for(auto v:g[u])dep.emplace_back(dfs(v));
        if(dep.empty())return 1;
        sort(dep.begin(),dep.end());
        for(int i=0;i<dep.size()-1;i++)b.emplace_back(dep[i]);
        return dep.back()+1;
    };
    for(int i=0;i<m;i++)if(par[i]==-1)b.emplace_back(dfs(i));
    sort(b.rbegin(),b.rend());
    for(int i=0;i<min(d,(int)b.size());i++)ans-=b[i];
    cout << ans;
}

Compilation message (stderr)

prison.cpp: In lambda function:
prison.cpp:47:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |         for(int i=0;i<dep.size()-1;i++)b.emplace_back(dep[i]);
      |                     ~^~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 10 / 10
• Subtask 3: 20 / 20
• Subtask 4: 10 / 10
• Subtask 5: 25 / 25
• Subtask 6: 20 / 20