Submission #482621

#	Time	Username	Problem	Language	Result	Execution time	Memory
482621		robell	Mobile (BOI12_mobile)	C++14	100 / 100	396 ms	35228 KiB

mobile

#pragma GCC optimize("O2")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag, tree_order_statistics_node_update> indexed_set;
typedef long long ll;
#define pb push_back
#define eb emplace_back
#define countbits __builtin_popcount
#define beg0 __builtin_clz
#define terminal0 __builtin_ctz
#define f first
#define s second
int mod=1e9+7;
void setIO(){
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
}
void setIO(string f){
	freopen((f+".in").c_str(),"r",stdin);
	freopen((f+".out").c_str(),"w",stdout);
	setIO();
}
ll N, L;
pair<ll,ll> pts[(int)1e6];
int main(){
	setIO(); cin >> N >> L;
	for (int i=0;i<N;i++){cin >> pts[i].f >> pts[i].s;}
	double l=1,r=1.5e9;
	while (abs(r-l)>1e-3){
		double mid = (l+r)/2;
		double pos = 0;
		for (int i=0;i<N;i++){
			double dist = sqrt(mid * mid - pts[i].s * pts[i].s);
			double xm = pts[i].f-dist, xma=pts[i].f+dist;
			if (xm<=pos) pos=max(pos,xma);
		}
		if (pos>=L) r=mid;
		else l=mid;
	}
	cout << fixed << setprecision(10) << l << "\n";
}

Compilation message (stderr)

mobile.cpp: In function 'void setIO(std::string)':
mobile.cpp:21:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |  freopen((f+".in").c_str(),"r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mobile.cpp:22:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |  freopen((f+".out").c_str(),"w",stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 4 / 4
• Subtask 3: 4 / 4
• Subtask 4: 4 / 4
• Subtask 5: 4 / 4
• Subtask 6: 5 / 5
• Subtask 7: 5 / 5
• Subtask 8: 5 / 5
• Subtask 9: 5 / 5
• Subtask 10: 5 / 5
• Subtask 11: 5 / 5
• Subtask 12: 5 / 5
• Subtask 13: 5 / 5
• Subtask 14: 5 / 5
• Subtask 15: 5 / 5
• Subtask 16: 5 / 5
• Subtask 17: 5 / 5
• Subtask 18: 5 / 5
• Subtask 19: 5 / 5
• Subtask 20: 5 / 5
• Subtask 21: 5 / 5