Submission #1185901

#	Time	Username	Problem	Language	Result	Execution time	Memory
1185901		Zbyszek99	Group Photo (JOI21_ho_t3)	C++20	100 / 100	28 ms	584 KiB

Main

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<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 siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
//mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll los(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 H[5001];
int dp[5001];
int real_poz[5001];
int big_cnt[5001];

int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    //random_start();
    int n;
    cin >> n;
    rep2(i,1,n) real_poz[i] = 1;
    rep2(i,1,n) cin >> H[i];
    vector<pii> inds = {{-1e9,1}};
    rep2(i,1,n) inds.pb({H[i],i});
    sort(all(inds));
    rep2(i,1,n)
    {
        rep2(j,inds[i].ss+1,n)
        {
            real_poz[j]++;
            if(inds[i].ff > H[j])
            {
                big_cnt[j]++;
            }
        }
        int cur_cost = 0;
        dp[i] = 1e9;
        for(int j = i; j >= 1; j--)
        {
            cur_cost += -big_cnt[inds[j].ss] + (i - real_poz[inds[j].ss]);
            dp[i] = min(dp[i],dp[j-1]+cur_cost);
        }
    }
    cout << dp[n] << "\n";
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 32 / 32
• Subtask 4: 20 / 20
• Subtask 5: 36 / 36