oj.uz

Submission #133117

# Submission time Handle Problem Language Result Execution time Memory
133117 2019-07-20T07:43:33 Z win11905 Mobile (BOI12_mobile) C++11
0 / 100
 257 ms 8704 KB 
#include <bits/stdc++.h>
#define pii pair<int, int>
#define x first
#define y second
using namespace std;

int n, k;
vector<pii> vec;

double dist(pii p, double x) {
    return hypot((double)p.x - x, (double)p.y);
}

double f(double x) { return x * x; }

double getx(pii p1, pii p2) {
    double x1 = p1.x, x2 = p2.x, y1 = p1.y, y2 = p2.y;
    return (f(x2) + f(y2) - f(x1) - f(y1)) / (2 * (x2 - x1));
}

int main() {
    scanf("%d %d", &n, &k);
    for(int i = 0, x, y; i < n; ++i) {
        scanf("%d %d", &x, &y);
        if(vec.empty()) vec.emplace_back(x, abs(y));
        else if(vec.back().x == x) vec.back().y = min(vec.back().y, abs(y));
        else vec.emplace_back(x, abs(y));
    }
    vector<pii> stk;
    stk.emplace_back(vec[0]), stk.emplace_back(vec[1]);
    for(int i = 2; i < vec.size(); ++i) {
        while(stk.size() >= 2 && getx(stk.back(), vec[i]) > getx(stk[stk.size()-2], vec[i])) stk.pop_back();
        stk.emplace_back(vec[i]);
    }
    double ans = 0;
    for(int i = 1; i < vec.size(); ++i) {
        double x = getx(vec[i], vec[i-1]);
        if(x >= 0 && x <= k) {
            ans = max(ans, dist(vec[i], x));
        }
    }
    printf("%.6f\n", ans);
}

Compilation message

mobile.cpp: In function 'int main()':
mobile.cpp:31:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 2; i < vec.size(); ++i) {
                    ~~^~~~~~~~~~~~
mobile.cpp:36:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 1; i < vec.size(); ++i) {
                    ~~^~~~~~~~~~~~
mobile.cpp:22:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &k);
     ~~~~~^~~~~~~~~~~~~~~~~
mobile.cpp:24:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &x, &y);
         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 376 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 376 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 376 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 376 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 380 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 376 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #7
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 21 ms 1520 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #8
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 19 ms 504 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #9
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 22 ms 1524 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #10
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 31 ms 864 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #11
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 32 ms 1520 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #12
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 119 ms 4580 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #13
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 135 ms 504 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #14
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 145 ms 8668 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #15
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 157 ms 588 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #16
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 169 ms 8696 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #17
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 182 ms 564 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #18
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 191 ms 8704 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #19
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 209 ms 524 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #20
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 237 ms 8704 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #21
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 257 ms 396 KB Output isn't correct
2 Halted 0 ms 0 KB -