Submission #895938

#	Time	Username	Problem	Language	Result	Execution time	Memory
895938		omsincoconut	Wish (LMIO19_noras)	C++17	100 / 100	225 ms	41920 KiB

noras

#include <bits/stdc++.h>

using namespace std;

typedef long long int lli;
typedef long double ld;
typedef pair<ld, ld> pld;
#define mp(x, y) make_pair(x, y)

const lli MAXN = 2e5+5;

lli N;
ld R;
pld ab[MAXN], cd[MAXN], vel[MAXN];

vector<pair<ld, lli>> events;

inline pld operator + (pld inp1, pld inp2) {
    return mp(inp1.first + inp2.first, inp1.second + inp2.second);
}

inline pld operator - (pld inp1, pld inp2) {
    return mp(inp1.first - inp2.first, inp1.second - inp2.second);
}

inline pld operator * (pld inp1, pld inp2) {
    return mp(inp1.first * inp2.first, inp1.second * inp2.second);
}

inline pld operator / (pld inp1, pld inp2) {
    return mp(inp1.first / inp2.first, inp1.second / inp2.second);
}

inline pld operator * (pld inp1, ld inp2) {
    return mp(inp1.first * inp2, inp1.second * inp2);
}

inline pld operator * (ld inp1, pld inp2) {
    return inp2*inp1;
}

inline pld operator / (pld inp1, ld inp2) {
    return mp(inp1.first / inp2, inp1.second / inp2);
}

inline pld operator / (ld inp1, pld inp2) {
    return inp2/inp1;
}

inline ld dist(pld inp) {
    return inp.first*inp.first + inp.second*inp.second;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> N >> R;
    for (lli i = 0; i < N; i++) cin >> ab[i].first >> ab[i].second >> cd[i].first >> cd[i].second;
    for (lli i = 0; i < N; i++) vel[i] = cd[i] - ab[i];

    for (lli i = 0; i < N; i++) {
        ld discrim = (2*ab[i].first*vel[i].first + 2*ab[i].second*vel[i].second)*(2*ab[i].first*vel[i].first + 2*ab[i].second*vel[i].second) - 4*dist(vel[i])*(dist(ab[i])-R*R);
        if (discrim < 0) continue;
        ld lessroot = ((2*ab[i].first*vel[i].first + 2*ab[i].second*vel[i].second)-sqrtl(discrim))/(2*dist(vel[i]));
        ld moreroot = ((2*ab[i].first*vel[i].first + 2*ab[i].second*vel[i].second)+sqrtl(discrim))/(2*dist(vel[i]));
        lessroot *= -1;
        moreroot *= -1;
        swap(lessroot, moreroot);
        //cout << i << " " << lessroot << " " << moreroot << "\n";
        if (moreroot < 0) continue;
        events.emplace_back(lessroot-(1e-10), 1);
        events.emplace_back(moreroot+(1e-10), -1);
    }
    sort(events.begin(), events.end());

    lli ans = 0;
    lli ct = 0;
    lli time = 0;
    for (lli i = 0; i < events.size(); i++) {
        time = floor(events[i].first);
        ct += events[i].second;
        while (i+1 < events.size() && time == floor(events[i+1].first)) {
            ct += events[i+1].second;
            i++;
        }
        ans = max(ans, ct);
    }
    cout << ans;
    return 0;
}

Compilation message (stderr)

noras.cpp: In function 'int main()':
noras.cpp:80:23: warning: comparison of integer expressions of different signedness: 'lli' {aka 'long long int'} and 'std::vector<std::pair<long double, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   80 |     for (lli i = 0; i < events.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~
noras.cpp:83:20: warning: comparison of integer expressions of different signedness: 'lli' {aka 'long long int'} and 'std::vector<std::pair<long double, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   83 |         while (i+1 < events.size() && time == floor(events[i+1].first)) {
      |                ~~~~^~~~~~~~~~~~~~~

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