Submission #731532

#	Time	Username	Problem	Language	Result	Execution time	Memory
731532		borisAngelov	Aliens (IOI16_aliens)	C++17	41 / 100	1035 ms	514500 KiB

aliens

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

const int maxn = 4005;
const long long inf = 1e18;

long long dp[maxn][maxn];
long long cost[maxn][maxn];

void divide(int k, int l, int r, int optl, int optr)
{
    if (l > r)
    {
        return;
    }

    int mid = (l + r) / 2;
    int best = optl;

    for (int i = optl; i <= min(optr, mid); ++i)
    {
        if (dp[k][mid] > dp[k - 1][i - 1] + cost[i][mid])
        {
            dp[k][mid] = dp[k - 1][i - 1] + cost[i][mid];
            best = i;
        }
    }

    if (l == r)
    {
        return;
    }

    divide(k, l, mid, optl, best);
    divide(k, mid + 1, r, best, optr);
}

long long calc(long long x)
{
    return x * x;
}

long long take_photos(int n, int m, int k, vector<int> r, vector<int> c)
{
    vector<pair<long long, long long>> v;

    for (int i = 0; i < n; ++i)
    {
        if (r[i] > c[i])
        {
            swap(r[i], c[i]);
        }

        v.push_back(make_pair(r[i], -c[i]));
    }

    sort(v.begin(), v.end());

    vector<pair<long long, long long>> v2;
    v2.push_back(make_pair(-1, -1));

    long long max_num = -1;

    for (int i = 0; i < n; ++i)
    {
        if (-v[i].second > max_num)
        {
            max_num = -v[i].second;
            v2.push_back(make_pair(v[i].first, -v[i].second));
        }
    }

    n = v2.size() - 1;
    k = min(k, n);

    for (int i = 0; i <= k; ++i)
    {
        for (int j = 0; j <= n; ++j)
        {
            dp[i][j] = inf;
        }
    }

    for (int j = 0; j <= k; ++j)
    {
        dp[j][0] = 0LL;
    }

    for (int i = 1; i <= n; ++i)
    {
        long long curr_max = 0;

        for (int j = i; j <= n; ++j)
        {
            curr_max = max(curr_max, v2[j].second);
            cost[i][j] = calc(curr_max - v2[i].first + 1) - (i > 1 ? calc(max(0LL, v2[i - 1].second - v2[i].first + 1)) : 0);
        }
    }

    for (int j = 1; j <= n; ++j)
    {
        dp[1][j] = cost[1][j];
    }

    for (int i = 2; i <= k; ++i)
    {
        divide(i, 1, n, 1, n);
    }

    return dp[k][n];
}

/*void fastIO()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int main()
{
    fastIO();

    int n, m, k;
    cin >> n >> m >> k;

    vector<int> r, c;

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

        r.push_back(x);
        c.push_back(y);
    }

    cout << "098d134608c94f7413faac591054ee35" << endl;
    cout << take_photos(n, m, k, r, c) << endl;

    return 0;
}*/

• Subtask 1: 4 / 4
• Subtask 2: 12 / 12
• Subtask 3: 9 / 9
• Subtask 4: 16 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40