Submission #1181953

#	Time	Username	Problem	Language	Result	Execution time	Memory
1181953		sleepntsheep	Cultivation (JOI17_cultivation)	C++20	0 / 100	1 ms	324 KiB

cultivation

//#pragma GCC optimize("O3,unroll-loops")
#include<stdio.h>
#include<set>
#include<algorithm>
#include<vector>

int r,c,n;long long ans=1e10;
std::vector<int>xx,yy;
struct pt{int x,y,cx,cy;}p[333];

struct DQ{
    int y[333*333],x[333*333],hd,tl;
    void cl(){ hd=0;tl=1; }
    DQ(){cl();}
    void ins(int t,int va){
	while(hd>=tl&&x[hd]<=va)--hd;
	++hd;
	x[hd]=va;
	y[hd]=t;
    }
    void tim(int t){ while(hd>=tl&&y[tl]<t)++tl; }
    int max(int t){ tim(t); return x[tl]; }
}L,R,LR;

template <typename T>
void sortunique(std::vector<T>&v){
    std::sort(v.begin(),v.end());
    v.resize(std::distance(v.begin(),std::unique(v.begin(),v.end())));
}

struct GAPMAINTAINER{
    std::multiset<int>s,gc;
    int l,r,g;
    void ins(int y){
	if(!s.count(y)){
	    auto it=s.upper_bound(y);
	    if(it!=s.end()&&(it)!=s.begin()){
		gc.erase(gc.find(*it-*prev(it)));
	    }
	    if(it!=s.end()) gc.insert(*it-y);
	    if((it)!=s.begin())gc.insert(y-*prev(it));
	    s.insert(y);
	    if(gc.size())
		g=*gc.rbegin()-1;
	    if(s.size()){
		l=*s.begin()-1;
		r=c-*s.rbegin();
	    }
	}else
	s.insert(y);
    }
    void rem(int y){
	if(s.count(y)==1){
	    auto it=s.upper_bound(y),iy=s.lower_bound(y);
	    if(it!=s.end())gc.erase(gc.find(*it-y));
	    if(iy!=s.begin())gc.erase(gc.find(y-*prev(iy)));
	    if(it!=s.end()&&iy!=s.begin())gc.insert(*it-*prev(iy));
	    s.erase(s.find(y));
	    if(gc.size())
		g=*gc.rbegin()-1;
	    if(s.size()){
		l=*s.begin()-1;
		r=c-*s.rbegin();
	    }
	}
	else
	s.erase(s.find(y));
    }
};

int pgap[333][333],plef[333][333],prig[333][333];

void precompute(){
    std::vector<int>tag[333];
    for(int i=0;i<n;++i) tag[p[i].cx].push_back(i);
    for(int i=0;i<(int)xx.size();++i){
	GAPMAINTAINER gm;
	for(int j=i;j<(int)xx.size();++j){
	    for(auto id:tag[j])gm.ins(p[id].y);
	    pgap[i][j]=gm.g;
	    plef[i][j]=gm.l;
	    prig[i][j]=gm.r;
	}
    }
}

int main(){
    scanf("%d%d%d",&r,&c,&n);
    for(int i=0;i<n;++i)scanf("%d%d",&p[i].x,&p[i].y),xx.push_back(p[i].x),yy.push_back(p[i].y);
    sortunique(xx),sortunique(yy);
    for(int i=0;i<n;++i)p[i].cx=std::lower_bound(xx.begin(),xx.end(),p[i].x)-xx.begin(),p[i].cy=std::lower_bound(yy.begin(),yy.end(),p[i].y)-yy.begin();
    precompute();

    std::sort(p,p+n,[](pt&a,pt&b){return a.y-b.y?a.y<b.y:a.x<b.x;});
    n=std::unique(p,p+n,[](pt&a,pt&b){return a.x==b.x&&a.y==b.y;})-p;

    auto CC=[&](int dw){
	L.cl();R.cl();LR.cl();

	int ban=0;
	auto Chk=[&](int i){
	    if(i<1)i=1;
	    std::vector<int>e;
	    for(int j=0;j<n;++j)if((p[j].x<=i&&p[j].x+dw>=i))
		e.push_back(p[j].y);
	    if(e.empty()){
		ban=i;
		return;
	    }
	    int gapmax=0;
	    for(int i=1;i<(int)e.size();++i)
		gapmax=std::max(gapmax,e[i]-e[i-1]-1);

	    L.ins(i,e[0]-1);
	    R.ins(i,c-e.back());
	    LR.ins(i,gapmax);

	    if(ban<=i-r)
		ans=std::min(ans,dw+0ll+std::max(L.max(i-r+1)+R.max(i-r+1),LR.max(i-r+1)));
	};

	std::vector<int>qwq;
	for(int i=0;i<n;++i){
	    qwq.push_back(p[i].x-1); qwq.push_back(p[i].x);
	    qwq.push_back(p[i].x+dw+1);
	    qwq.push_back(p[i].x+dw);
	}
	std::sort(qwq.begin(),qwq.end());
	qwq.resize(std::distance(qwq.begin(),std::unique(qwq.begin(),qwq.end())));
	for(auto dw:qwq)Chk(dw);
    };

    auto CC_=[&](int dw){
	L.cl();R.cl();LR.cl();

	enum{ ADD,DEL,CHK };
	struct Event{ int type,x,cx; };
	std::vector<Event>etag[333];
	int ban{};
	for(int i=0;i<n;++i){
	    auto&e1=etag[p[i].cx];
	    e1.push_back((Event){ADD,p[i].x,p[i].cx});
	    e1.push_back((Event){DEL,p[i].x+dw+1,p[i].cx});
	    e1.push_back((Event){CHK,p[i].x+dw,p[i].cx});
	    e1.push_back((Event){CHK,p[i].x+dw+1,p[i].cx});
	    e1.push_back((Event){CHK,p[i].x,p[i].cx});
	    e1.push_back((Event){CHK,p[i].x-1,p[i].cx});
	}

	static int qu[999],hd,tl,l1,r1;
	hd=0;tl=1;

	for(int x1_=0;x1_<(int)xx.size();++x1_){
	    for(auto&ee:etag[x1_]){
		int x=ee.x;
		if(ee.type==ADD){
		    qu[++hd]=ee.cx;
		}else if(ee.type==DEL){
		    ++tl;
		}else{
		    if(hd>=tl){
			l1=qu[tl],r1=qu[hd];
			L.ins(ee.x,plef[l1][r1]);
			R.ins(ee.x,prig[l1][r1]);
			LR.ins(ee.x,pgap[l1][r1]);
		    }else ban=x;
		    if(ban<=ee.x-r)
			ans=std::min(ans,dw+0ll+std::max(L.max(x-r+1)+R.max(x-r+1),LR.max(x-r+1)));
		}
	    }
	    if(hd<tl)ban=xx[x1_];
	}
    };

    std::vector<int>ud_cands={0};

    {
	std::sort(p,p+n,[](pt&a,pt&b){return a.x-b.x?a.x<b.x:a.y<b.y;});
	std::vector<int>uu={p[0].x-1},dd={r-p[n-1].x};
	for(int i=0;i<n;++i){
	    uu.push_back(p[i].x-1);
	    dd.push_back(r-p[i].x);
	    for(int j=i;j<n;++j)
		if(p[j].x>p[i].x)
		    ud_cands.push_back(p[j].x-p[i].x-1);
	}
	for(auto u:uu)for(auto d:dd)ud_cands.push_back(u+d);
	std::sort(ud_cands.begin(),ud_cands.end());
	ud_cands.resize(std::distance(ud_cands.begin(),std::unique(ud_cands.begin(),ud_cands.end())));
    }

    std::sort(p,p+n,[](pt&a,pt&b){return a.y-b.y?a.y<b.y:a.x<b.x;});
    for(auto ud:ud_cands)CC_(ud);

    printf("%lld\n",ans);
    return 0;
}

Compilation message (stderr)

cultivation.cpp: In function 'int main()':
cultivation.cpp:88:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |     scanf("%d%d%d",&r,&c,&n);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~
cultivation.cpp:89:30: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |     for(int i=0;i<n;++i)scanf("%d%d",&p[i].x,&p[i].y),xx.push_back(p[i].x),yy.push_back(p[i].y);
      |                         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 30
• Subtask 5: 0 / 20
• Subtask 6: 0 / 20