Submission #287459

#	Time	Username	Problem	Language	Result	Execution time	Memory
287459		TadijaSebez	Cultivation (JOI17_cultivation)	C++11	100 / 100	136 ms	2680 KiB

cultivation

#include <bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define ll long long
void ckmn(ll&a,ll b){a=min(a,b);}
void ckmx(int&a,int b){a=max(a,b);}
const int N=305;
const int inf=1e9+7;
int sz[N],SWX[N][N],SWU[N][N],SWD[N][N],SWR[N][N],x[N],y[N],n,H,W;
int L[N],lsz,T[N],tsz,SM[N*N],U[N*N],D[N*N],R[N*N],ssz,esz;
pii evs[N];
void unq(int*a,int&n){sort(a+1,a+1+n);n=unique(a+1,a+1+n)-a-1;}
int main(){
	scanf("%i %i %i",&H,&W,&n);
	for(int i=1;i<=n;i++){
		scanf("%i %i",&x[i],&y[i]);
		L[++lsz]=y[i]-1;
		if(y[i]>1)T[++tsz]=y[i]-1;
	}
	T[++tsz]=W;unq(T,tsz);
	for(int i=1;i<=tsz;i++){
		esz=0;
		for(int j=1;j<=n;j++){
			if(y[j]<=T[i]){
				SM[++ssz]=T[i]-y[j];
				evs[++esz]={T[i]-y[j],x[j]};
			}
		}
		multiset<int> dif,pts;
		pts.insert(0);pts.insert(H+1);
		dif.insert(H+1);
		sort(evs+1,evs+1+esz);
		for(int j=1,k;j<=esz;j=k){
			for(k=j;k<=esz&&evs[j].first==evs[k].first;k++){
				auto it=pts.insert(evs[k].second);
				dif.erase(dif.find(*next(it)-*prev(it)));
				dif.insert(*next(it)-*it);
				dif.insert(*it-*prev(it));
			}
			sz[i]++;
			SWX[i][sz[i]]=evs[j].first;
			SWU[i][sz[i]]=H-*prev(prev(pts.end()));
			SWD[i][sz[i]]=*next(pts.begin())-1;
			SWR[i][sz[i]]=*dif.rbegin()-1;
		}
	}
	unq(L,lsz);
	unq(SM,ssz);
	ll ans=inf*2;
	for(int i=lsz,j=tsz-1;i>=1;i--){
		for(;j>=1&&L[i]<T[j];j--){
			for(int k=1,o=1;k<=ssz;k++){
				while(o<=sz[j]&&SWX[j][o]<=SM[k])o++;
				if(o>1)ckmx(U[k],SWU[j][o-1]),ckmx(D[k],SWD[j][o-1]),ckmx(R[k],SWR[j][o-1]);
				else U[k]=inf,D[k]=inf,R[k]=inf;
			}
		}
		auto Try=[&](int k,int o){
			int r=max(SM[k]-L[i],SWX[tsz][o]);
			int _d=max(D[k],SWD[tsz][o]);
			int _u=max(U[k],SWU[tsz][o]);
			int _r=max(R[k],SWR[tsz][o]);
			ckmn(ans,(ll)max(_r,_u+_d)+r+L[i]);
		};
		for(int k=1,o=1;k<=ssz;k++){
			for(;o<=sz[tsz]&&SWX[tsz][o]<=SM[k]-L[i];o++)
				if(k>1)Try(k-1,o);
			if(o>1)Try(k,o-1);
			if(k==ssz)for(;o<=sz[tsz];o++)Try(k,o);
		}
	}
	printf("%lld\n",ans);
	return 0;
}

Compilation message (stderr)

cultivation.cpp: In function 'int main()':
cultivation.cpp:14:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   14 |  scanf("%i %i %i",&H,&W,&n);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~
cultivation.cpp:16:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   16 |   scanf("%i %i",&x[i],&y[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~

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