Submission #248626

#	Time	Username	Problem	Language	Result	Execution time	Memory
248626		thebes	Mobile (BOI12_mobile)	C++14	100 / 100	948 ms	27592 KiB

mobile

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,ssse3,sse3,sse4,popcnt,avx,mmx,abm,tune=native")
#include <bits/stdc++.h>
using namespace std;

const int MN = 1e6+6;
const long double eps = 1e-4;
int N, L, i, j, x, y;
pair<int,int> vec[MN];
long double lo, hi, mid, rad, f, s, a, b, cur;

int main(){
    scanf("%d%d",&N,&L);
    for(i=1;i<=N;i++){
        scanf("%d%d",&x,&y);
        y = abs(y);
        vec[i]={x,y};
    }
    lo=0, hi=1e9;
    while(lo+eps<hi){
        mid=(lo+hi)/2;
        cur = eps;
        for(i=1;i<=N;i++){
            if(mid<vec[i].second) continue;
            else{
                rad = sqrt(mid*mid-(long double)vec[i].second*vec[i].second);
                a=vec[i].first-rad, b=vec[i].first+rad;
            }
            if(b>cur&&a<=cur) cur=b;
            if(cur>=L) break;
        }
        if(cur>=L) hi=mid;
        else lo=mid+eps;
    }
    printf("%.4Lf\n",lo);
    return 0;
}

Compilation message (stderr)

mobile.cpp: In function 'int main()':
mobile.cpp:14:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&N,&L);
     ~~~~~^~~~~~~~~~~~~~
mobile.cpp:16:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&x,&y);
         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 4 / 4
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