Submission #330758

#TimeUsernameProblemLanguageResultExecution timeMemory
330758IgorIAliens (IOI16_aliens)C++17
Compilation error
0 ms0 KiB
#include <bits/stdc++.h>

using namespace std;

const long long INFLL = 1e18;

pair<long long, long long> calc(int n, long long M, vector<int> l, vector<int> r)
{
    vector<long long> dp(n, INFLL);
    vector<long long> bl(n, INFLL);
    for (int i = 0; i < n; i++)
        dp[i] = M + 1ll * (r[i] - l[0] + 1) * (r[i] - l[0] + 1), bl[i] = 1;
    struct line{
        long long k, b, id;
    };
    vector<line> convex;
    int lj = 0;
    for (int i = 0; i < n; i++)
    {
        long long res = 1ll * r[i] * r[i];
        long long d = INFLL, used = 0;
        for (int j = 0; j < convex.size(); j++)
        {
            line e = convex[j];
            if (e.b + e.k * r[i] < d)
            {
                d = e.b + e.k * r[i], used = INFLL;
                lj = j;
            }
            if (e.b + e.k * r[i] == d && bl[e.id] < used)
            {
                used = bl[e.id];
                lj = j;
            }
            if (j > lj + 1)
                break;
        }
        res += d;
        if (res < dp[i])
            dp[i] = res, bl[i] = used + 1;
        if (i + 1 < n)
        {
            long long b = dp[i] + 1ll * l[i + 1] * l[i + 1] + 1 - 2 * l[i + 1] + M - 1ll * max(0, r[i] - l[i + 1] + 1) * max(0, r[i] - l[i + 1] + 1);
            long long k = 2 * (1 - l[i + 1]);
            line L = {k, b, i};
            while (convex.size() >= 2)
            {
                line A = convex[convex.size() - 2];
                line B = convex[convex.size() - 1];
                if (1ll * (B.b - L.b) * (L.k - B.k) > 1ll * (A.b - L.b) * (L.k - B.k))
                    convex.pop_back();
                else
                    break;
            }
            convex.push_back(L);
        }
    }
    //cout << M << " " << dp[n - 1] << " " << bl[n - 1] << endl;
    return {dp[n - 1], bl[n - 1]};
}

long long take_photos(int n, int m, int k, vector<int> l, vector<int> r)
{
    vector<int> cv(m);
    for (int i = 0; i < m; i++)
    {
        cv[i] = i + 1;
    }
    for (int i = 0; i < n; i++)
    {
        int x = min(l[i], r[i]);
        int y = max(l[i], r[i]);
        cv[y] = min(cv[y], x);
    }
    l.clear();
    r.clear();
    for (int i = 0; i < m; i++)
    {
        if (cv[i] <= i)
        {
            while (l.size() && l.back() >= cv[i])
                l.pop_back(), r.pop_back();
            l.push_back(cv[i]), r.push_back(i);
        }
    }
    n = l.size();
    //for (int i = 0; i < l.size(); i++)
    //    cout << l[i] << " " << r[i] << endl;
    long long L = 0, R = 1ll * m * m + 222;
    long long ans = INFLL;
    k = min(k, n);
    while (L + 1 < R)
    {
        long long M = (L + R) / 2;
        if (calc(n, M, l, r).second >= k)
            L = M;
        else
            R = M;
    }
    for (long long d = R - 1; d <= R; d++)
    {
        pair<long long, long long> res = calc(n, d, l, r);
        //cout << res.first << " " << res.second << " " << d << " " << k << endl;
        if (res.second <= k)
            ans = min(ans, res.first - 1ll * k * d);
    }
    return ans;
}

void solve(int g, vector<int> &l, vector<int> &r, vector<vector<long long> > &dp, int le_i, int ri_i, int le_p, int ri_p)
{
    if (le_i > ri_i) return;
    int mid_i = (le_i + ri_i) / 2;
    int id = le_p;
    for (int p = le_p; p <= ri_p && p < mid_i; p++)
    {
        long long res = dp[p][g - 1];
        long long L = l[p], R = r[mid_i - 1], covto = -1;
        if (p) covto = r[p - 1];
        if (covto < L)
            res += 1ll * (R - L + 1) * (R - L + 1);
        else
            res += 1ll * (R - L + 1) * (R - L + 1) - 1ll * (covto - L + 1) * (covto - L + 1);
        if (res < dp[mid_i][g])
        {
            id = p;
            dp[mid_i][g] = res;
        }
    }
    solve(g, l, r, dp, le_i, mid_i - 1, le_p, id);
    solve(g, l, r, dp, mid_i + 1, ri_i, id, ri_p);
}

long long take_photos2(int n, int m, int k, vector<int> l, vector<int> r)
{
    vector<int> cv(m);
    for (int i = 0; i < m; i++)
    {
        cv[i] = i + 1;
    }
    for (int i = 0; i < n; i++)
    {
        int x = min(l[i], r[i]);
        int y = max(l[i], r[i]);
        cv[y] = min(cv[y], x);
    }
    l.clear();
    r.clear();
    for (int i = 0; i < m; i++)
    {
        if (cv[i] <= i)
        {
            while (l.size() && l.back() >= cv[i])
                l.pop_back(), r.pop_back();
            l.push_back(cv[i]), r.push_back(i);
        }
    }
    n = l.size();
    const long long INFLL = 1e18;
    vector<vector<long long> > dp(n + 1, vector<long long>(k + 1, INFLL));
    dp[0][0] = 0;
    for (int g = 1; g <= k; g++)
    {
        solve(g, l, r, dp, 1, n, 0, n);
    }
    return *min_element(dp[n].begin(), dp[n].end());
}

signed main()
{
    freopen("80", "r", stdin);
    srand(time(NULL));
    int n, m, k;
    cin >> n >> m >> k;
    while (1)
    {
        vector<int> r(n), c(n);
        for (int i = 0; i < n; i++)
        {
            //r[i] = rand() % m;
            //c[i] = rand() % m;
            //cout << r[i] << " " << c[i] << endl;
            cin >> r[i] >> c[i];
        }
        long long a = take_photos(n, m, k, r, c);
        long long b = take_photos2(n, m, k, r, c);
        cout << a << endl << b << endl << endl;
        //if (a != b)
            return 0;
    }
}

Compilation message (stderr)

aliens.cpp: In function 'std::pair<long long int, long long int> calc(int, long long int, std::vector<int>, std::vector<int>)':
aliens.cpp:22:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<calc(int, long long int, std::vector<int>, std::vector<int>)::line>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |         for (int j = 0; j < convex.size(); j++)
      |                         ~~^~~~~~~~~~~~~~~
aliens.cpp: In function 'int main()':
aliens.cpp:171:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  171 |     freopen("80", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~
/tmp/cchGe3eN.o: In function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/ccxBPcvu.o:aliens.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status