Submission #18001

#	Time	Username	Problem	Language	Result	Execution time	Memory
18001		comet	Dancing Elephants (IOI11_elephants)	C++98	73 / 100	9000 ms	22380 KiB

elephants

#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;

int N,M,L;
int B=400;

int sz[400],p[400][710],cnt[400][710],nxt[400][710];

void bucket_init(int k){
	int id=sz[k]-1;
	for(int i=sz[k]-1;i>=0;i--){
		if(p[k][sz[k]-1]-p[k][i]<=L)cnt[k][i]=1,nxt[k][i]=p[k][i]+L+1;
		else{
			while(p[k][id]-p[k][i]>L)id--;
			cnt[k][i]=cnt[k][id+1]+1;
			nxt[k][i]=nxt[k][id+1];
		}
	}
}

void push(int k,int x){
	int id=0;
	while(id<sz[k]&&p[k][id]<=x)id++;
	sz[k]++;
	for(int i=sz[k]-1;i>id;i--)p[k][i]=p[k][i-1];
	p[k][id]=x;
	bucket_init(k);
}
void pop(int k,int x){
	int id=0;
	while(p[k][id]<=x)id++;
	for(int i=id;i<sz[k];i++)p[k][i-1]=p[k][i];
	sz[k]--;
	bucket_init(k);
}

struct elephant{
	int p,group_id,id;
	bool operator<(const elephant& r)const{
		return p<r.p;
	}
}b[150010];

int ID[150010];

void renewal(){
	sort(b,b+N);
	memset(sz,0,sizeof(sz));
	for(int i=0;i<N;i++){
		ID[b[i].id]=i;
		b[i].group_id=i/B;
		p[i/B][sz[i/B]++]=b[i].p;
		M=max(M,i/B+1);
	}
	for(int i=0;i<M;i++){
		bucket_init(i);
	}
}

void init(int N_, int L_, int X[]){
	N=N_;
	L=L_;
	for(int i=0;i<N;i++)b[i]=elephant{X[i],i/B,i};
	renewal();
}

int findGroup(int x){
	if(p[0][0]>x)return 0;
	for(int i=0;i<M-1;i++){
		if(p[i][0]<=x&&x<p[i+1][0])return i;
	}
	return M-1;
}

int calc(){
	int x=0,ret=0;
	for(int i=0;i<M;i++){
		int id=lower_bound(p[i],p[i]+sz[i],x)-p[i];
		if(id==sz[i])continue;
		ret+=cnt[i][id];
		x=nxt[i][id];
	}
	return ret;
}

int update(int i, int y){

	int id=b[ID[i]].group_id;
	pop(id,b[ID[i]].p);
	b[ID[i]].p=y;
	if(sz[id]==0){
		renewal();
		return calc();
	}

	id=b[ID[i]].group_id=findGroup(y);
	push(id,y);
	if(sz[id]>700)renewal();
	return calc();
}

• Subtask 1: 10 / 10
• Subtask 2: 16 / 16
• Subtask 3: 0 / 24
• Subtask 4: 47 / 47
• Subtask 5: 0 / 3