제출 #990072

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
990072		vyshniak_n	Group Photo (JOI21_ho_t3)	C++17	100 / 100	435 ms	141068 KiB

Main

//#pragma GCC optimize ("Ofast")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target ("avx2")

#include <iostream>
#include <cmath>
#include <algorithm>
#include <stdio.h>
#include <cstdint>
#include <cstring>
#include <string>
#include <cstdlib>
#include <vector>
#include <bitset>
#include <map>
#include <queue>
#include <ctime>
#include <stack>
#include <set>
#include <list>
#include <random>
#include <deque>
#include <functional>
#include <iomanip>
#include <sstream>
#include <fstream>
#include <complex>
#include <numeric>
#include <cassert>
#include <array>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <thread>

typedef long long ll;
typedef long double ld;

#define el '\n'
#define ff first
#define ss second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define point pair <ll, ll>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

using namespace std;

mt19937_64 rnd(time(0));

const ll INF = 1e18 + 10;
const ll inf = 1e9 + 10;
const ll N = 5e3 + 10;
const ll mod = 1e9 + 7;
const ll K = 400;
const ll LOG = 25;

ll cost[N][N], dp[N], h[N], fen[N], invH[N]; 

void upd(ll v) {
    for (; v < N; v = (v | (v + 1)))
        fen[v] += 1;
}
ll get(ll v) {
    ll res = 0;
    for (; v >= 0; v = (v & (v + 1)) - 1)
        res += fen[v];
    return res;
}

void solve() {
    ll n;
    cin >> n;

    for (ll i = 1; i <= n; i++)
        cin >> h[i], invH[h[i]] = i;

    for (ll l = 1; l <= n; l++) {
        vector <ll> pos(n + 1), suff(n + 2);
        for (ll i = 1; i < l; i++)
            suff[invH[i]]++;
        for (ll i = n; i >= 1; i--)
            suff[i] += suff[i + 1];
        for (ll i = l; i <= n; i++)
            pos[i] = invH[i] + suff[invH[i]];
        for (ll i = 0; i < N; i++)  
            fen[i] = 0;
        
        for (ll r = l; r <= n; r++) {
            cost[l][r] = cost[l][r - 1] + (pos[r] - l) - (get(n) - get(pos[r]));
            upd(pos[r]);
        }
    }

    for (ll i = 1; i <= n; i++) {
        dp[i] = INF;
        for (ll j = 0; j < i; j++)
            dp[i] = min(dp[i], dp[j] + cost[j + 1][i]);
    }
    cout << dp[n] << el;
    return;
}
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    ll tests = 1;
    //cin >> tests;

    while (tests--) 
        solve();
    return 0;
}
/*
*/

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