제출 #388971

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
388971		tostes	Mobile (BOI12_mobile)	C++17	100 / 100	679 ms	35396 KiB

mobile

#include<bits/stdc++.h>
//#include<iostream>
//#include<vector>
using namespace std;
#define _ << ' ' <<
#define pb push_back
#define all(x) begin(x), end(x)
#define mp make_pair
#define f first
#define s second
#define sz(x) int((x).size())
using ll = long long;
using db = long double;
using pl = pair<ll,ll>;
using pi = pair<int,int>;

vector < pair<double,double> > pt;
int n; 
double l;

bool pos(double k){
	double sm=0;
	for(int i=0; i<n; i++){
		if(abs(pt[i].s)>=k) continue;
		double sq = sqrt(k*k-pt[i].s*pt[i].s);
		if(pt[i].f-sq<=sm) sm=max(sm,pt[i].f+sq);
	}
	return sm>=l;
}

int main(){
//	ios::sync_with_stdio(false);
 //	cin.tie(0);
	//freopen("loan.in", "r", stdin);
	//freopen("loan.out", "w", stdout);
	scanf("%d %lf", &n, &l);
	pt.resize(n);
	for(auto &x: pt) scanf("%lf %lf", &x.f, &x.s);
	double lo=0, hi=1e10;

	while((hi-lo)>0.00001){
		double mid=(lo+hi)/2;
		if(pos(mid)) hi=mid;
		else lo=mid;
	}
	printf("%.6lf\n", lo);
}

컴파일 시 표준 에러 (stderr) 메시지

mobile.cpp: In function 'int main()':
mobile.cpp:36:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   36 |  scanf("%d %lf", &n, &l);
      |  ~~~~~^~~~~~~~~~~~~~~~~~
mobile.cpp:38:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   38 |  for(auto &x: pt) scanf("%lf %lf", &x.f, &x.s);
      |                   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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