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Submission #86948

# Submission time Handle Problem Language Result Execution time Memory
86948 2018-11-28T17:10:18 Z popovicirobert Mobile (BOI12_mobile) C++14
100 / 100
 761 ms 73652 KB 
#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
// 217
// 44

using namespace std;

const double eps = 1e-9;
const double INF = 1e18;
const int MAXN = (int) 1e6;

struct Point {
    double x, y;
}pts[MAXN + 1];

inline double dist(Point a, Point b) {
    return sqrt(1LL * (a.x - b.x) * (a.x - b.x) + 1LL * (a.y - b.y) * (a.y - b.y));
}

struct Data {
    double l, r;
    int id;
};

vector <Data> stk;

inline bool eq(double a, double b) {
    return fabs(a - b) < eps;
}

double L;

inline bool ok(double &l, double &r, Point b) {
    Point a = pts[stk.back().id];
    if(eq(a.x, b.x)) {
        return 0;
    }
    double x = 1.0 * (b.x * b.x + b.y * b.y - a.x * a.x - a.y * a.y) / (2 * (b.x - a.x));
    if(x > L) {
        return 0;
    }
    x = max(x, (double) 0.0);
    if(x - stk.back().l > 0) {
        stk.back().r = x;
        l = x;
        r = L;
        return 0;
    }
    l = stk.back().l;
    r = L;
    return 1;
}

int main() {
    //ifstream cin("B.in");
    //ofstream cout("B.out");
    int i, n;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    cin >> n >> L;
    int sz = 0;
    for(i = 1; i <= n; i++) {
        double x, y;
        cin >> x >> y;
        y = fabs(y);
        if(sz > 0 && eq(x, pts[sz].x)) {
            pts[sz].y = min(pts[sz].y, y);
        }
        else {
            pts[++sz] = {x, y};
        }
    }
    n = sz;
    stk.push_back({0, L, 1});
    for(i = 2; i <= n; i++) {
        double l = INF, r = -INF;
        while(!stk.empty()) {
            if(ok(l, r, pts[i])) {
                stk.pop_back();
            }
            else {
                break;
            }
        }
        if(r - l > 0) {
            stk.push_back({l, r, i});
        }
    }
    double ans = 0;
    for(auto it : stk) {
        ans = max(ans, dist(pts[it.id], {it.l, 0}));
        ans = max(ans, dist(pts[it.id], {it.r, 0}));
    }
    cout << fixed << setprecision(20) << ans;
    //cin.close();
    //cout.close();
    return 0;
}

Subtask #1
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 416 KB Output is correct
4 Correct 2 ms 420 KB Output is correct

Subtask #2
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 472 KB Output is correct
2 Correct 2 ms 560 KB Output is correct
3 Correct 2 ms 560 KB Output is correct
4 Correct 2 ms 612 KB Output is correct

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 612 KB Output is correct
2 Correct 3 ms 760 KB Output is correct
3 Correct 3 ms 760 KB Output is correct
4 Correct 4 ms 796 KB Output is correct

Subtask #4
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 796 KB Output is correct
2 Correct 5 ms 844 KB Output is correct
3 Correct 5 ms 844 KB Output is correct
4 Correct 5 ms 988 KB Output is correct

Subtask #5
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 988 KB Output is correct
2 Correct 5 ms 1104 KB Output is correct
3 Correct 4 ms 1104 KB Output is correct
4 Correct 5 ms 1352 KB Output is correct

Subtask #6
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 1352 KB Output is correct
2 Correct 5 ms 1376 KB Output is correct
3 Correct 4 ms 1376 KB Output is correct
4 Correct 5 ms 1500 KB Output is correct
5 Correct 5 ms 1500 KB Output is correct

Subtask #7
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 46 ms 3416 KB Output is correct
2 Correct 54 ms 4328 KB Output is correct
3 Correct 39 ms 4896 KB Output is correct
4 Correct 60 ms 6236 KB Output is correct
5 Correct 30 ms 6236 KB Output is correct

Subtask #8
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 45 ms 6352 KB Output is correct
2 Correct 49 ms 7548 KB Output is correct
3 Correct 51 ms 9144 KB Output is correct
4 Correct 57 ms 10456 KB Output is correct
5 Correct 60 ms 12132 KB Output is correct

Subtask #9
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 51 ms 16020 KB Output is correct
2 Correct 60 ms 16020 KB Output is correct
3 Correct 51 ms 16320 KB Output is correct
4 Correct 90 ms 16320 KB Output is correct
5 Correct 54 ms 16320 KB Output is correct

Subtask #10
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 66 ms 16320 KB Output is correct
2 Correct 64 ms 16320 KB Output is correct
3 Correct 59 ms 16320 KB Output is correct
4 Correct 75 ms 16320 KB Output is correct
5 Correct 65 ms 16320 KB Output is correct

Subtask #11
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 74 ms 16392 KB Output is correct
2 Correct 73 ms 16392 KB Output is correct
3 Correct 55 ms 16392 KB Output is correct
4 Correct 84 ms 16392 KB Output is correct
5 Correct 72 ms 16392 KB Output is correct

Subtask #12
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 307 ms 34228 KB Output is correct
2 Correct 333 ms 34228 KB Output is correct
3 Correct 335 ms 34228 KB Output is correct
4 Correct 375 ms 34228 KB Output is correct
5 Correct 304 ms 34228 KB Output is correct

Subtask #13
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 346 ms 34228 KB Output is correct
2 Correct 306 ms 34228 KB Output is correct
3 Correct 310 ms 34228 KB Output is correct
4 Correct 363 ms 34228 KB Output is correct
5 Correct 316 ms 34228 KB Output is correct

Subtask #14
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 346 ms 48064 KB Output is correct
2 Correct 382 ms 48064 KB Output is correct
3 Correct 360 ms 48064 KB Output is correct
4 Correct 486 ms 48064 KB Output is correct
5 Correct 377 ms 48064 KB Output is correct

Subtask #15
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 414 ms 48064 KB Output is correct
2 Correct 366 ms 48064 KB Output is correct
3 Correct 318 ms 48064 KB Output is correct
4 Correct 450 ms 48064 KB Output is correct
5 Correct 366 ms 48064 KB Output is correct

Subtask #16
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 392 ms 49708 KB Output is correct
2 Correct 446 ms 49708 KB Output is correct
3 Correct 439 ms 49708 KB Output is correct
4 Correct 599 ms 49708 KB Output is correct
5 Correct 406 ms 49708 KB Output is correct

Subtask #17
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 507 ms 49708 KB Output is correct
2 Correct 460 ms 49708 KB Output is correct
3 Correct 418 ms 49708 KB Output is correct
4 Correct 510 ms 49708 KB Output is correct
5 Correct 515 ms 49708 KB Output is correct

Subtask #18
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 443 ms 51116 KB Output is correct
2 Correct 544 ms 51116 KB Output is correct
3 Correct 517 ms 51116 KB Output is correct
4 Correct 619 ms 51116 KB Output is correct
5 Correct 480 ms 51116 KB Output is correct

Subtask #19
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 526 ms 51116 KB Output is correct
2 Correct 512 ms 51116 KB Output is correct
3 Correct 491 ms 51116 KB Output is correct
4 Correct 640 ms 51116 KB Output is correct
5 Correct 526 ms 51116 KB Output is correct

Subtask #20
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 578 ms 54268 KB Output is correct
2 Correct 701 ms 54268 KB Output is correct
3 Correct 654 ms 54268 KB Output is correct
4 Correct 756 ms 54268 KB Output is correct
5 Correct 627 ms 54268 KB Output is correct

Subtask #21
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 761 ms 54268 KB Output is correct
2 Correct 615 ms 54268 KB Output is correct
3 Correct 597 ms 54268 KB Output is correct
4 Correct 716 ms 61308 KB Output is correct
5 Correct 688 ms 73652 KB Output is correct