Submission #1158465

#	Time	Username	Problem	Language	Result	Execution time	Memory
1158465		murpyl	Mobile (BOI12_mobile)	C++20	8 / 100	180 ms	15940 KiB

mobile

#include <bits/stdc++.h>
using namespace std;
#define int long long
using ll = long long;
using vi = vector<int>;
#define pb push_back
#define rsz resize
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
using pi = pair<int,int>;
#define endl "\n"
#define mp make_pair
void setIO(string name = "") {
	ios_base::sync_with_stdio(0); cin.tie(0);
	if(sz(name)){
		freopen((name+".in").c_str(), "r", stdin); 
		freopen((name+".out").c_str(), "w", stdout);
	}
}

signed main(){
    setIO();
    int n,L;
    cin>>n>>L;
    vector<pi> arr(n);
    for (int i = 0; i < n; i++){
        cin>>arr[i].first>>arr[i].second;
    }
    double l = 1, r = 1.5e9;
    while (r-l > 1e-3){
        double mid = (l+r)/2;
        double curr = 0;
        for (int i = 0; i < n; i++){
            double delta = sqrt(mid*mid - arr[i].second*arr[i].second);
            double left = arr[i].first - delta;
            double right = arr[i].first + delta;
            if (left <= curr){
                curr = max(curr, right);
            }
        }
        if (curr >= L) r = mid;
        else l = mid;
    }
    cout<<l<<endl;
}

Compilation message (stderr)

mobile.cpp: In function 'void setIO(std::string)':
mobile.cpp:16:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |                 freopen((name+".in").c_str(), "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mobile.cpp:17:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |                 freopen((name+".out").c_str(), "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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