제출 #1174374

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1174374		Hamed_Ghaffari	Group Photo (JOI21_ho_t3)	C++20	100 / 100	61 ms	492 KiB

Main

#include<bits/stdc++.h>
using namespace std;

using ll = long long;
using pll = pair<ll, ll>;
#define all(x) x.begin(), x.end()
#define pb push_back

const int MXN = 5005;

int n, inv[MXN], pos[MXN], a[MXN], dp[MXN];

int32_t main() {
    cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);
    cin >> n;
    for(int i=1; i<=n; i++) cin >> a[i];
    for(int i=n-1; i>=1; i--) {
        int lst=0;
        for(int j=1; j<=n; j++)
            if(a[j]>=i)
                pos[a[j]] = lst++;
        for(int j=i+1; j<=n; j++)
            if(pos[j]<pos[i]) inv[j]++;
        int cur=0;
        dp[i] = 2e9;
        for(int j=i; j<=n; j++) {
            cur += pos[j] - inv[j];
            dp[i] = min(dp[i], cur+dp[j+1]);
        }
    }
    cout << dp[1] << '\n';
    return 0;
}

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