Submission #444011

#	Time	Username	Problem	Language	Result	Execution time	Memory
444011		yungyao	The short shank; Redemption (BOI21_prison)	C++17	100 / 100	1375 ms	277788 KiB

prison

using namespace std;
#include <iostream>
#include <algorithm>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <utility>
#include <vector>
#include <memory.h>
#include <deque>

typedef long long LL;
typedef pair<int,int> pii;
#define l first
#define r second
#define mkp make_pair
#define iter(x) x.begin(),x.end()
#define MEM(s,e) memset(s,e,sizeof(s))

const int maxn = 2e6+200;

int s[maxn];
vector <int> tree[maxn];

struct node{
    pii iv;
    int idx;
    node (pii iv,int i): iv(iv), idx(i) {}
};

vector <int> val;
int dfs(int x){
    vector <int> ret;
    for (auto i:tree[x]){
        ret.push_back(dfs(i));
    }
    sort(iter(ret),[](int a,int b){return a > b;});
    for (int i=1;i<ret.size();++i) val.push_back(ret[i]);
    return 1 + (ret.empty() ? 0 : ret[0]);
}

int main(){
    int n,d,t;
    stack <pii> sk;
    vector <pii> iv;

    cin >> n >> d >> t;
    int ans = n;
    for (int i=1;i<=n;++i){
        if (sk.size() and sk.top().r < i) sk.pop();
        cin >> s[i];
        if (s[i] > t){
            if (sk.empty())
                --ans;
            else
                iv.push_back(mkp(sk.top().l,i));
        }

        if (s[i] < t){
            pii x = mkp(i,i + t - s[i]);
            while (sk.size() and x.r >= sk.top().r) sk.pop();
            sk.push(x);
        }
    }

    sort (iter(iv),[](pii a,pii b){return a.l != b.l ? a.l < b.l : a.r > b.r;});

    stack <node> dfss;
    vector <int> roots;
    for (int i=0;i<iv.size();++i){
        while (dfss.size() and iv[i].l > dfss.top().iv.r) dfss.pop();

        if (dfss.empty()) roots.push_back(i);
        else tree[dfss.top().idx].push_back(i);
        dfss.push(node(iv[i],i));
    }

    for (auto i:roots){
        val.push_back(dfs(i));
    }
    sort (iter(val),[](int a,int b){return a > b;});

    for (int i=0;i<min(d,int(val.size()));++i) ans -= val[i];
    cout << ans;

    return 0;
}

Compilation message (stderr)

prison.cpp: In function 'int dfs(int)':
prison.cpp:39:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |     for (int i=1;i<ret.size();++i) val.push_back(ret[i]);
      |                  ~^~~~~~~~~~~
prison.cpp: In function 'int main()':
prison.cpp:71:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |     for (int i=0;i<iv.size();++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