Submission #305253

#	Time	Username	Problem	Language	Result	Execution time	Memory
305253		oleksg	Mobile (BOI12_mobile)	C++14	0 / 100	1099 ms	48116 KiB

mobile

#include <fstream>
#include <string>
#include <iostream>
#include <math.h>
#include <algorithm>
#include<bits/stdc++.h>
#include <vector>
using namespace std;

long long n, l;
vector<pair<long long, long long>> points;

bool ok(double cur){
    vector<pair<double, double>> segs;
    for (long long x = 0; x < points.size(); x++){
        double curx = points[x].first;
        double cury = abs(points[x].second);
        double xintervals = sqrt(pow(cur, 2) - pow(cury, 2));
        double minx = max((double)0, curx - xintervals);
        double maxx = min((double)l, curx + xintervals);
        if (minx <= l && maxx >= 0){
            segs.push_back(make_pair(minx, maxx));
        }
    }
    sort(segs.begin(), segs.end());
    if (segs[0].first > 0){
        return false;
    }
    double curx = 0;
    for (long long x = 0; x < segs.size(); x++){
        if (segs[x].second > curx){
            if (segs[x].first <= curx){
                curx = segs[x].second;
            }
            else{
                return false;
            }
        }
    }
    if (curx < l){
        return false;
    }
    return true;
}
int main(){
    long long one, two;
    cin >> n >> l;
    for (int x = 0; x < n; x++){
        cin >> one >> two;
        points.push_back(make_pair(one, two));
    }
    double mi = 0;
    double ma = 10000000000;
    while(ma - mi > 0.0001){
        double cur = (mi + ma) / 2.0;
        if (ok(cur)){
            ma = cur;
        }
        else{
            mi = cur + 0.0001;
        }
    }
    cout << setprecision(20) << ma;
}

Compilation message (stderr)

mobile.cpp: In function 'bool ok(double)':
mobile.cpp:15:29: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |     for (long long x = 0; x < points.size(); x++){
      |                           ~~^~~~~~~~~~~~~~~
mobile.cpp:30:29: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<double, double> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |     for (long long x = 0; x < segs.size(); x++){
      |                           ~~^~~~~~~~~~~~~

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