Submission #643324

#	Time	Username	Problem	Language	Result	Execution time	Memory
643324		pls33	Wish (LMIO19_noras)	C++17	100 / 100	243 ms	19272 KiB

noras

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#pragma region dalykai
using p32 = pair<int, int>;
using p32u = pair<uint32_t, uint32_t>;
using p64 = pair<int64_t, int64_t>;
using p64u = pair<uint64_t, uint64_t>;
using vi16 = vector<int16_t>;
using vi16u = vector<uint16_t>;
using vi32 = vector<int>;
using vi32u = vector<uint32_t>;
using vi64 = vector<int64_t>;
using vi64u = vector<uint64_t>;
using vp32 = vector<p32>;
using vp32u = vector<p32u>;
using vp64 = vector<p64>;
using vp64u = vector<p64u>;
using vvi32 = vector<vi32>;
using vvi32u = vector<vi32u>;
using vvi64 = vector<vi64>;
using vvi64u = vector<vi64u>;
using vvp32 = vector<vp32>;
using vvp32u = vector<vp32u>;
using vvp64 = vector<vp64>;
using vvp64u = vector<vp64u>;

using pf32 = pair<float, float>;
using pf64 = pair<double, double>;
using pf80 = pair<long double, long double>;
using vf32 = vector<float>;
using vf64 = vector<double>;
using vf80 = vector<long double>;
using vpf32 = vector<pf32>;
using vpf64 = vector<pf64>;
using vpf80 = vector<pf80>;
using vvf32 = vector<vf32>;
using vvf64 = vector<vf64>;
using vvf80 = vector<vf80>;
using vvpf32 = vector<vpf32>;
using vvpf64 = vector<vpf64>;
using vvpf80 = vector<vpf80>;

template <typename key, typename val>
using ord_map = tree<key, val, less<key>, rb_tree_tag,
                     tree_order_statistics_node_update>;

template <typename key>
using ord_set = tree<key, null_type, less<key>, rb_tree_tag,
                     tree_order_statistics_node_update>;

const int BUF_SZ = 1 << 15;
inline namespace fast_in
{
    char buf[BUF_SZ];
    int pos;
    int len;

    char next_char(FILE *f)
    {
        if (pos == len)
        {
            pos = 0;
            len = (int)fread(buf, 1, BUF_SZ, f);

            if (!len)
            {
                return EOF;
            }
        }

        return buf[pos++];
    }

    int read_int(FILE *f)
    {
        int x;
        char ch;
        int sgn = 1;

        while (!isdigit(ch = next_char(f)))
        {
            if (ch == '-')
            {
                sgn *= -1;
            }
        }

        x = ch - '0';
        while (isdigit(ch = next_char(f)))
        {
            x = x * 10 + (ch - '0');
        }

        return x * sgn;
    }
}

/**
 * @brief gale programos flush_out kviest!!
 */
inline namespace fast_out
{
    char buf[BUF_SZ];
    int pos;

    void flush_out(FILE *f)
    {
        fwrite(buf, 1, pos, f);
        pos = 0;
    }

    void write_char(char c, FILE *f)
    {
        if (pos == BUF_SZ)
        {
            flush_out(f);
        }

        buf[pos++] = c;
    }

    void write_int(int x, FILE *f)
    {
        static char num_buf[100];

        if (x < 0)
        {
            write_char('-', f);
            x *= -1;
        }

        int len = 0;
        for (; x >= 10; x /= 10)
        {
            num_buf[len++] = (char)('0' + (x % 10));
        }

        write_char((char)('0' + x), f);
        while (len)
        {
            write_char(num_buf[--len], f);
        }
        write_char('\n', f);
    }
}
#pragma endregion

__int128_t mult(int64_t a, int64_t b)
{
    return __int128_t(a) * b;
}

__int128_t square(int64_t a)
{
    return mult(a, a);
}

struct func_t
{
    __int128_t a, b, c;

    func_t(p64 star, p64 speed)
    {
        a = square(speed.first) + square(speed.second);
        b = 2 * (mult(star.first, speed.first) + mult(star.second, speed.second));
        c = square(star.first) + square(star.second);
    }

    __int128_t eval(int64_t x)
    {
        return a * x * x + b * x + c;
    }
};

bool point_in_circle(p64 p, int64_t radius)
{
    __int128_t x = square(p.first);
    __int128_t y = square(p.second);

    __int128_t r = square(radius);

    return x + y <= r;
}

int64_t find_peak(func_t func, int64_t right = 1e9 + 1)
{
    int64_t l = -1, r = right;
    while (r - l > 1)
    {
        int64_t mid = (l + r) >> 1;

        if (func.eval(mid) < func.eval(mid + 1))
        {
            r = mid;
        }
        else
        {
            l = mid + 1;
        }
    }

    return l + 1;
}

int64_t find_bound(int64_t peak, int64_t radius, func_t func,
                   bool decrease, int upper = 1e9 + 1)
{
    if (func.eval(peak) > radius * radius)
    {
        return -1;
    }
    int mult = decrease ? -1 : 1;

    int64_t res = 0;
    for (int64_t index = 30; index >= 0; index--)
    {
        int64_t cur = peak + mult * (res + (1 << index));
        if (cur < 0 || cur > upper)
        {
            continue;
        }

        __int128_t val = func.eval(cur);
        if (val > radius * radius)
        {
            continue;
        }

        res += 1 << index;
    }

    return peak + mult * res;
}

p64 find_range(p64 star, p64 speed, int64_t radius)
{
    func_t distance(star, speed);

    // int64_t peak = find_peak(distance);
    int64_t peak_l = -distance.b / (2 * distance.a);
    int64_t peak_r = peak_l + 1;

    peak_l = clamp(peak_l, int64_t(0), int64_t(1e9 + 1));
    peak_r = clamp(peak_r, int64_t(0), int64_t(1e9 + 1));

    int64_t left = find_bound(peak_l, radius, distance, true);
    int64_t right = find_bound(peak_r, radius, distance, false);

    if (left == right && right == -1)
    {
        return {-1, -1};
    }

    if (left == -1)
    {
        return {right, right};
    }
    else if (right == -1)
    {
        return {left, left};
    }

    return {left, right};
}

int main()
{
#ifndef _AAAAAAAAA
    ios_base::sync_with_stdio(false);
    cin.tie(0);
#else
    freopen("noras.in", "r", stdin);
#ifndef __linux__
    atexit([]()
           {
        freopen("con", "r", stdin);
        system("pause"); });
#endif
#endif

    int64_t n, radius;
    cin >> n >> radius;

    vp64 star(n),
        speed(n);
    for (int i = 0; i < n; i++)
    {
        int64_t a, b, c, d;
        cin >> a >> b >> c >> d;

        star[i] = {a, b};
        speed[i] = {c - a, d - b};
    }

    vp64 ranges;
    for (size_t i = 0; i < n; i++)
    {
        p64 time = find_range(star[i], speed[i], radius);

        if (time == make_pair<int64_t, int64_t>(-1, -1))
        {
            continue;
        }

        ranges.emplace_back(time.first, 1);
        ranges.emplace_back(time.second, -1);
    }

    sort(ranges.begin(), ranges.end(),
         [](p64 a, p64 b)
         {
             return (a.first == b.first) ? a.second > b.second : a.first < b.first;
         });

    int64_t count = 0;
    int64_t result = 0;

    for (auto &r : ranges)
    {
        count += r.second;
        result = max(count, result);
    }

    cout << result << '\n';

    return 0;
}

Compilation message (stderr)

noras.cpp:8: warning: ignoring '#pragma region dalykai' [-Wunknown-pragmas]
    8 | #pragma region dalykai
      | 
noras.cpp:151: warning: ignoring '#pragma endregion ' [-Wunknown-pragmas]
  151 | #pragma endregion
      | 
noras.cpp: In function 'int main()':
noras.cpp:301:26: warning: comparison of integer expressions of different signedness: 'size_t' {aka 'long unsigned int'} and 'int64_t' {aka 'long int'} [-Wsign-compare]
  301 |     for (size_t i = 0; i < n; i++)
      |                        ~~^~~

• Subtask 1: 23 / 23
• Subtask 2: 23 / 23
• Subtask 3: 15 / 15
• Subtask 4: 32 / 32
• Subtask 5: 7 / 7