Submission #841614

#	Time	Username	Problem	Language	Result	Execution time	Memory
841614		a5a7	Mobile (BOI12_mobile)	C++14	4 / 100	1088 ms	90980 KiB

mobile

#include <bits/stdc++.h>
#define ALL(x) (x).begin(), (x).end()
#define REP(i, a, b) for (int i = (a); i < (b); i++)
#define READ(arr, n) for (int i = 0; i < (n); i++) cin >> arr[i];
#define ABS(a) (max((a), -(a)))
using namespace std;
typedef long long ll;
typedef long double ld;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n; ld l;
    cin >> n >> l;
    pair<ld, ld> stations[n];
    ld r = 0;
    for (int i = 0; i < n; i++) {
        cin >> stations[i].first >> stations[i].second;
        r = max(r, sqrtl(max((ld) 0, (l-stations[i].first)*(l-stations[i].first)-stations[i].second*stations[i].second)));
    }
    ld le = 0;
    while ((r-le)>0.0001){
        ld m = (le+r)/2;
        vector<pair<ld, ld>> ranges;
        for (int i = 0; i < n; i++){
            if (ABS(stations[i].second) >= m) continue;
            ld sq = sqrtl(m * m - stations[i].second * stations[i].second);
            ranges.push_back({stations[i].first-sq, stations[i].first+sq});
        }
        sort(ALL(ranges));
        ld loc = 0;
        for (int i = 0; i < ranges.size(); i++){
            if (loc > ranges[i].first){
                loc = max(loc, ranges[i].second);
            }
        }
        if (loc >= l){
            r = m;
        }else{
            le = m;
        }
    }
    cout << le << endl;
}

Compilation message (stderr)

mobile.cpp: In function 'int main()':
mobile.cpp:32:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long double, long double> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         for (int i = 0; i < ranges.size(); i++){
      |                         ~~^~~~~~~~~~~~~~~

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