Submission #872510

#	Time	Username	Problem	Language	Result	Execution time	Memory
872510		imarn	Balloons (CEOI11_bal)	C++14	100 / 100	177 ms	5128 KiB

bal

#include<bits/stdc++.h>
#define pb push_back
#define f first
#define ld long double
#define s second
#define vll vector<ll>
#define vi vector<int>
#define sz(x) (int)x.size()
using namespace std;
ld inf=1e18;
bool qm;
struct line {
    mutable ld m,c,p;
    line(ld p) : m(0),c(inf),p(p){};
    line(ld m,ld c) : m(m),c(c),p(inf){};
    bool operator<(const line &o)const{return qm?p<o.p:m>o.m;}
};
struct convexhull:multiset<line>{
    bool isect(iterator x,iterator y){
        if(y==end())return x->p=inf,0;
        if(x->m==y->m)x->p=x->c<=y->c?inf:-inf;
        else x->p=(x->c-y->c)/(y->m-x->m);
        return x->p>=y->p;
    }
    void add(ld m,ld c){
        auto y=insert(line(m,c)),x=y,z=next(y);
        while(isect(y,z))z=erase(z);
        while(x!=begin()&&isect(--x,y))isect(x,erase(y));
        while((y=x)!=begin()&&(--x)->p>=y->p)isect(x,erase(y));
    }
    ld get(ld x){
        if(empty())return inf;
        qm=1;auto u=lower_bound(line(x));qm=0;
        return u->m*x+u->c;
    }
}cht;
int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    int n;cin>>n;
    ld a[n];
    ld x,r;cin>>x>>r;a[0]=r;
    cht.add(1.0/(2.0*sqrt(r)),-x/(2.0*sqrt(r)));
    for(int i=1;i<n;i++){
        cin>>x>>r;ld y = cht.get(x);
        r = min(r,y*y);a[i]=r;
        cht.add(1.0/(2.0*sqrt(r)),-x/(2.0*sqrt(r)));
    }
    for(int i=0;i<n;i++)cout<<fixed<<setprecision(3)<<a[i]<<"\n";
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10