Submission #996475

#	Time	Username	Problem	Language	Result	Execution time	Memory
996475		amine_aroua	Group Photo (JOI21_ho_t3)	C++17	0 / 100	1 ms	348 KiB

Main

#include <bits/stdc++.h>
//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
using namespace std;
#define int long long
#define pb push_back
#define nl '\n'
#define fore(i, y) for(int i = 0; i < y; i++)
#define forr(i, x, y) for(int i = x;i<=y;i++)
#define forn(i, y, x) for(int i = y; i >= x; i--)
const int INF = 1e18;
signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n ;
    cin>>n;
    vector<int> h(n + 1) , dp(n + 1 , INF) , pos(n + 1);
    forr(i , 1 , n)
    {
        cin>>h[i];
        pos[h[i]] = i;
    }
    dp[0] = 0;
    vector<vector<int>> prevInv(n + 1 , vector<int>(n + 1 , 0));
    vector<vector<int>> cost = prevInv;
    forr(i , 1 ,n)
    {
        forr(j , 1 , n)
        {
            prevInv[i][j] = prevInv[i][j - 1] + (pos[j] > pos[i]);
        }
    }
    forr(i , 1 , n)
    {
        forr(j , i , n)
        {
            cost[i][j]+=prevInv[i - 1][j];
            if(i < j)
            {
                cost[i][j]+= cost[i][j - 1];
                cost[i][j]+= (j - i);
                cost[i][j]-= (prevInv[j][j - 1] - prevInv[j][i - 1]);
            }
        }
    }
    forr(i , 1 , n)
        forr(j , 1 , i)
            dp[i] = min(dp[i] , dp[j - 1] + cost[j][i]);
    cout<<dp[n]<<nl;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 7
• Subtask 3: 0 / 32
• Subtask 4: 0 / 20
• Subtask 5: 0 / 36