Submission #691750

#	Time	Username	Problem	Language	Result	Execution time	Memory
691750		abysmal	Group Photo (JOI21_ho_t3)	C++14	100 / 100	550 ms	98532 KiB

Main

#include<iostream>
#include<stdio.h>
#include<stdint.h>
#include<vector>
#include<algorithm>
#include<utility>
#include<set>
#include<map>
#include<queue>
#include<stack>
#include<deque>
#include<string>
#include<assert.h>
#include<math.h>
#include<chrono>
#include<random>
#include<bitset>

using namespace std;

const int64_t INF = (int64_t) 1e9 + 5;
const int64_t mINF = (int64_t) 4 * 1e4;
const int64_t MOD = (int64_t) 1e9 + 7;
const int nbit = 30;
const int ndig = 10;
const int nchar = 26;
const int p1 = 31;
const int p2 = 53;
const int D = 4;
int dr[D] = {0, 1, 0, -1};
int dc[D] = {1, 0, -1, 0};
// 0 right // 1 down // 2 left // 3 up

struct Solution
{
    int n;
    Solution() {}

    void solve()
    {
        cin >> n;

        vector<int> pos(n, -1);
        for(int i = 1; i <= n; i++)
        {
            int x;
            cin >> x;

            pos[x - 1] = i;
        }

        vector<vector<int> > cost(n, vector<int>(n, 0));
        vector<int> bit(n + 1, 0);
        for(int i = 0; i < n; i++)
        {
            update(pos[i], 1, bit);
        }

        for(int j = 0; j < n; j++)
        {
            update(pos[j], -1, bit);
            for(int i = j; i >= 0; i--)
            {
                if(i != j) cost[i][j] += cost[i + 1][j];

                cost[i][j] += sum(pos[i] - 1, bit);
            }
        }

        for(int i = 0; i < n; i++)
        {
            vector<int> bit2(n + 1, 0);

            int x = 0;
            for(int j = i; j < n; j++)
            {
                x += sum(pos[j], bit2);
                cost[i][j] += x;

                update(pos[j], 1, bit2);
            }
        }

        vector<int> dp(n + 1, INF);
        dp[0] = 0;
        for(int i = 1; i <= n; i++)
        {
            for(int j = i; j <= n; j++)
            {
                dp[j] = min(dp[j], dp[i - 1] + cost[i - 1][j - 1]);
            }
        }

        cout << dp[n] << "\n";
    }

    int sum(int i, vector<int>& bit)
    {
        int ans = 0;
        while(i > 0)
        {
            ans += bit[i];

            i -= (i & (-i));
        }

        return ans;
    }

    void update(int i, int val, vector<int>& bit)
    {
        while(i < (int) bit.size())
        {
            bit[i] += val;

            i += (i & (-i));
        }
    }

    int modsub(int t1, int t2)
    {
        int64_t res = t1 - t2;
        if(res < 0) res += MOD;

        return res;
    }

    int modadd(int t1, int t2)
    {
        int64_t res = t1 + t2;
        if(res >= MOD) res -= MOD;

        return res;
    }

    int modmul(int t1, int t2)
    {
        int64_t res = 1LL * t1 * t2;
        return (res % MOD);
    }

    bool BIT(int mask, int j)
    {
        return (mask & MASK(j));
    }

    int64_t MASK(int j)
    {
        return (1LL << j);
    }

    int64_t Abs(int64_t t1)
    {
        if(t1 < 0) return -t1;
        return t1;
    }
};

void __startup()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);

//    freopen("in.txt", "r", stdin);
//    freopen("out.txt", "w", stdout);
}

int main()
{
    __startup();
    int t = 1;
//    cin >> t;

    for(int i = 1; i <= t; i++)
    {
        Solution().solve();
    }

    return 0;
}

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