Submission #1056912

#	Time	Username	Problem	Language	Result	Execution time	Memory
1056912		Zbyszek99	The short shank; Redemption (BOI21_prison)	C++17	0 / 100	2 ms	604 KiB

prison

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define size(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace std;
//mt19937 mt;void random(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll rand(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

int n,d,t; 
vector<int> v;

int DP[4001][4001];
int ans_pair[4001][4001];

int count_f(int l, int r)
{
    int ans = 0;
    int max_end = -1;
    rep2(i,l,r)
    {
        max_end = max(max_end,i + t-v[i]);
   //     if(l == r) cout << max_end << " me\n";
        if(i <= max_end) ans++;
        ans_pair[l][i] = ans;
    }
}

void solve()
{
    cin >> n >> d >> t;
    v.resize(n);
    rep(i,n) cin >> v[i];
    if(n * d * d<= 10000000)
    {
        rep(i,n)
        {
            count_f(i,n-1);
        }
        rep(i,n)
        {
            DP[i][0] = ans_pair[0][i];
        }
        rep2(j,1,d)
        {
            rep(i,n)
            {
                int min_ = 1e9;
                rep2(k,max(0,n-d-3),i+1)
                {
                    int dod = 0;
                    if(k != 0) dod = DP[k-1][j-1];
                    min_ = min(min_,dod + ans_pair[k][i]);
                }       
                DP[i][j] = min_;
                //cout << DP[i][j] << " " << i << " " << j << "\n";
            }
        }
        cout << DP[n-1][d];
    }
    else
    {
        vector<int> ans_pref(n);
        vector<int> ans_suf(n+1,0);
        int max_end = -1;
        int ans = 0;
        rep(i,n)
        {
            if(v[i] <= t)
            {
                max_end = max(max_end,i + t-v[i]);
            }
            if(i <= max_end)
            {
                ans++;
            }
            ans_pref[i] = ans;
        }
        reverse(all(v));
        ans = 0;
        int pop = -1;
        set<int> untake;
        rep(i,n)
        {
            if(v[i] <= t)
            {
                int odl = t-v[i];
                ans++;
            //   if(size(untake) != 0) cout << *untake.begin() << " untake\n";
                while(size(untake) != 0 && -(*untake.begin()) >= i - odl)
                {
                    ans++;
                    untake.erase(untake.begin());
                }
                ans_suf[n-i-1] = ans;
            }
            else 
            {
                ans_suf[n-i-1] = ans;
                untake.insert(-i);
            }
        }
        int ans_ = n;
        rep(i,n)
        {
            //cout << ans_pref[i] << " " << ans_suf[i] << " ans\n";
            if(i == n-1)
            {
                ans_ = min(ans_,ans_pref[n-1]);
            }
            else ans_ = min(ans_,ans_pref[i]+ans_suf[i+1]);
        }
        cout << ans_ << "\n";
    }
}

int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    //random();
    int t = 1;
    //cin >> t;
    while(t--) solve();
}

Compilation message (stderr)

prison.cpp: In function 'int count_f(int, int)':
prison.cpp:40:1: warning: no return statement in function returning non-void [-Wreturn-type]
   40 | }
      | ^
prison.cpp: In function 'void solve()':
prison.cpp:94:13: warning: unused variable 'pop' [-Wunused-variable]
   94 |         int pop = -1;
      |             ^~~
prison.cpp:72:23: warning: array subscript -1 is below array bounds of 'int [4001][4001]' [-Warray-bounds]
   72 |         cout << DP[n-1][d];
      |                 ~~~~~~^
prison.cpp:26:5: note: while referencing 'DP'
   26 | int DP[4001][4001];
      |     ^~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 10
• Subtask 3: 0 / 20
• Subtask 4: 0 / 10
• Subtask 5: 0 / 25
• Subtask 6: 0 / 20