Submission #708327

#	Time	Username	Problem	Language	Result	Execution time	Memory
708327		tamyte	Wish (LMIO19_noras)	C++14	0 / 100	1 ms	212 KiB

noras

#include <bits/stdc++.h>

using namespace std;
#define sz(x) (int)(x).size()
void setIO(string name = "") {
    cin.tie(0)->sync_with_stdio(0); // see /general/fast-io
    if (sz(name)) {
        freopen((name + ".in").c_str(), "r", stdin); // see /general/input-output
        freopen((name + ".out").c_str(), "w", stdout);
    }
}

/*----------------------------------*/

typedef long long ll;


struct star
{
    long long x, y;
    long long dx, dy;
} stars[(int)2e5 + 1];


long long max_t(int i, long long r) {
    if (stars[i].dx == 0) {
        return abs(r - stars[i].y) / abs(stars[i].dy);
    } else if (stars[i].dy == 0) {
        return abs(r - stars[i].x) / abs(stars[i].dx);
    }
    return max(abs(r - stars[i].x) / abs(stars[i].dx), 
        abs(r - stars[i].y) / abs(stars[i].dy));
}

int main() {
    setIO("");
    int n;
    ll r;
    cin >> n >> r;
    for (int i = 0; i < n; ++i) {
        cin >> stars[i].x >> stars[i].y >> stars[i].dx >> stars[i].dy;
        stars[i].dy = stars[i].dy - stars[i].y;
        stars[i].dx = stars[i].dx - stars[i].x;
        // cout << stars[i].dx << " : " << stars[i].dy << "\n";
    }
    vector<long long> start, finish;
    for (int i = 0; i < n; ++i) {
        long long left = 0, right = max_t(i, r);
        // cerr << left << " " << right << "\n";
        while (left < right) {
            long long mid = (left + right) / 2;
            long long cx = stars[i].x + stars[i].dx * mid;
            long long cy = stars[i].y + stars[i].dy * mid;
            // cerr << cx << " " << cy << " : ";
            if (cx * cx + cy * cy > r * r && (cx <= 0 || cy <= 0)) {
                left = mid + 1;
            } else if (cx * cx + cy * cy == r * r) {
                left = mid;
                break;
            } else {
                right = mid - 1;
            }
            // cerr << left << " " << right << "\n";
        }
        if ((stars[i].x + stars[i].dx * left) * (stars[i].x + stars[i].dx * left)
            + (stars[i].y + stars[i].dy * left) * (stars[i].y + stars[i].dy * left) <= r * r) start.push_back(left);
        else continue;
        // cerr << left << " -> ";
        right = 1000000000000LL;
        while (left < right) {
            long long mid = (left + right) / 2;
            long long cx = stars[i].x + stars[i].dx * mid;
            long long cy = stars[i].y + stars[i].dy * mid;
            // cerr << cx << " " << cy << " - ";
            // cerr << left << " " << right << "\n";
            if (cx * cx + cy * cy > r * r) {
                right = mid - 1;
            } else {
                left = mid + 1;
            }
        }
        finish.push_back(left);
        // cout << left << "\n";
    }
    sort(start.begin(), start.end());
    sort(finish.begin(), finish.end());
    int ii = 0, jj = 0;
    int curr = 0, mx = 0;
    while (ii < start.size()) {
        for (; ii < start.size() && start[ii] <= finish[jj]; ++ii) curr++;
        mx = max(curr, mx);
        curr--;
        jj++;
    }
    cout << mx;
}

Compilation message (stderr)

noras.cpp: In function 'int main()':
noras.cpp:89:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   89 |     while (ii < start.size()) {
      |            ~~~^~~~~~~~~~~~~~
noras.cpp:90:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   90 |         for (; ii < start.size() && start[ii] <= finish[jj]; ++ii) curr++;
      |                ~~~^~~~~~~~~~~~~~
noras.cpp: In function 'void setIO(std::string)':
noras.cpp:8:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 |         freopen((name + ".in").c_str(), "r", stdin); // see /general/input-output
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
noras.cpp:9:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |         freopen((name + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 23
• Subtask 2: 0 / 23
• Subtask 3: 0 / 15
• Subtask 4: 0 / 32
• Subtask 5: 0 / 7