Submission #44808

#	Time	Username	Problem	Language	Result	Execution time	Memory
44808		leehosu01	먼 별 (KOI16_dist)	C++17	0 / 100	57 ms	1636 KiB

dist

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
#define F(X) (X<0?-1:X>0)
ll T,MT,N,tms,bst=1ll<<62ll;
struct A{
int x,y,dx,dy;void SC(){cin>>x>>y>>dx>>dy;}
ll lcx(){return T*dx+x;}
ll lcy(){return T*dy+y;}
bool operator<(const A&X)const{return T*dx+x==T*X.dx+X.x?T*dy+y<T*X.dy+X.y:T*dx+x<T*X.dx+X.x;}
ll Ds(A&X){return (lcx()-X.lcx())*(lcx()-X.lcx())+(lcy()-X.lcy())*(lcy()-X.lcy());}
}S[30000];
int cp(ll*X,ll*Y)
{
    ll T=0;
    for(int i=0;i<3;i++)
        T+=X[i]*Y[i+1]-X[i+1]*Y[i];
    return F(T);
}
int ccw(A&x0,A&x1,A&x2)
{
    A XA[4]={x0,x1,x2,x0};
    ll XX[4],YY[4];
    for(int i=0;i<4;i++)
    {
        XX[i]=XA[i].lcx();
        YY[i]=XA[i].lcy();
    }
    return cp(XX,YY);
}
bool used[30000];
#define nxt(X,Xp) Xp=X;if(++Xp==cov.end())Xp=cov.begin()
inline ld slop(A&d1,A&d2)
{
    return ((ld)d1.lcx()-d2.lcx())/(d1.lcy()-d2.lcy());
}
const ld RAD=180/(ld)3.14159265358979646323;
inline ld slopRNG(ld x1,ld x2,ld x3)//각도상[0]<=[1]<=[2]에서 1반환
{
    ld AT[3],SP[3]={x1,x2,x3};
    for(int i=0;i<3;i++)AT[i]=atan(SP[i]);
    return (AT[0]<=AT[1]&&AT[1]<=AT[2]);
}
ll pro(int Ts)
{
    memset(used,0,sizeof(used));

    list<int>::iterator s1,s2;
    list<int>cov;
    T=Ts;
    sort(S,S+N);
    int K=1;
    for(int i=0;i>=0;i+=K)
    {
        if(i==N)K=-1,s1=cov.begin(),s2=--cov.end();
        if(i!=0&&used[i])continue;
        while(cov.size()>=2&&ccw(S[--cov.back()],S[cov.back()],S[i])==1){used[cov.back()]=0;cov.pop_back();}
        used[i]=1;cov.push_back(i);
    }//시작정점은 2번들어간다.

    ll MX=0;
    /*list<int>::iterator I,Ip,J=cov.begin(),Jp,Jpp;
    for(I=cov.begin();I!=cov.end();I++)
    {
        nxt(I,Ip);
        ld SPI=slop(S[*I],S[*Ip]);
        nxt(J,Jp);
        nxt(Jp,Jpp);
        while(!slopRNG(slop(S[*J],S[*Jp]),SPI,slop(S[*Jp],S[*Jpp]))){J=Jp;Jp=Jpp;nxt(Jp,Jpp);printf("c");}
        MX=max(MX,S[*I].Ds(S[*Jp]));
        printf("A");
    }
        printf("B");
        */

    list<int>::iterator I=s1,It,J=s2,Jt;
    do{
        It=I;++It;
        Jt=J;++Jt;
        if(Jt==cov.end())break;
        MX=max(MX,S[*I].Ds(S[*J]));
        MX=max(MX,S[*I].Ds(S[*Jt]));
        MX=max(MX,S[*It].Ds(S[*J]));
        MX=max(MX,S[*It].Ds(S[*Jt]));
        if(slop(S[*I],S[*It])<slop(S[*J],S[*Jt]))++I;
        else ++J;
    }while(I!=s2&&J!=cov.end());
    if(MX<bst)bst=MX,tms=Ts;
    return MX;
}

void rnd(ll&X)
{
    ull T=rand();
    for(int i=0;i<=10;i++)T^=((ull)rand()<<(rand()%64));
    X=(T>>1)%(MT+1);
}
int main()
{
    /*while(1)
    {
        ll X[4],Y[4];
        cin>>X[0]>>X[1]>>X[2];
        cin>>Y[0]>>Y[1]>>Y[2];
        X[3]=X[0];
        Y[3]=Y[0];
        ll T=0;
        for(int i=0;i<3;i++)
            T+=X[i]*Y[i+1]-X[i+1]*Y[i];
        printf("%d\n",F(T));
    }*/

    int i;
    cin>>N>>MT;
    for(i=0;i<N;i++)S[i].SC();
    ll l=0,r=MT,m,PS[3],minl,minI;
    while(l<r)
    {
        m=l+r>>1;
        minl=1ll<<62ll;
        for(i=-1;i<2;i++)
        {
            if(m+i>=0&&m+i<=MT)
            {
                PS[i+1]=pro(m+i);
                if(PS[i+1]<minl)
                {
                    minl=PS[i+1];
                    minI=i;
                }
            }
        }
        if(minI==-1)r=m-1;
        else if(minI==0)l=r=m;
        else l=m+1;
    }
    cout<<tms<<'\n'<<bst;

}

Compilation message (stderr)

dist.cpp: In function 'int main()':
dist.cpp:121:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
         m=l+r>>1;
           ~^~
dist.cpp:135:9: warning: 'minI' may be used uninitialized in this function [-Wmaybe-uninitialized]
         if(minI==-1)r=m-1;
         ^~

• Subtask 1: 0 / 2
• Subtask 2: 0 / 40
• Subtask 3: 0 / 39
• Subtask 4: 0 / 19