Submission #16422

#	Time	Username	Problem	Language	Result	Execution time	Memory
16422		choyi0521	Dancing Elephants (IOI11_elephants)	C++98	Compilation error	0 ms	0 KiB

elephants

#include "elephants.h"
#include<algorithm>
using namespace std;
const int MAX_N = 150000, MAX_RTN =388;
int n,l,x[MAX_N];
int rtn;
struct st{
	int sz;
	int x[MAX_RTN*2],d[MAX_RTN * 2],cnt[MAX_RTN*2];
}e[MAX_RTN];
void init(int N, int L, int X[]){
	n = N;
	l = L;
	rtn = sqrt(N);
	for (int i = 0; i < N; i++)
		e[i / rtn].x[e[i / rtn].sz++]=x[i] = X[i];
}
void UpdateBucket(int b){
	int tpos = e[b].sz;
	for (int i = e[b].sz - 1; i >= 0; i--){
		while (e[b].x[tpos - 1] - e[b].x[i] > l) tpos--;
		if (tpos == e[b].sz){
			e[b].d[i] = e[b].x[i];
			e[b].cnt[i] = 1;
		}
		else{
			e[b].d[i] = e[b].d[tpos];
			e[b].cnt[i] = e[b].cnt[tpos] + 1;
		}
	}
}
void Restructure(){
	sort(x, x + n);
	for (int i = 0; i <= rtn; i++) e[i].sz = 0;
	for (int i = 0; i < n; i++)
		e[i / rtn].x[e[i / rtn].sz++] = x[i];
	for (int i = 0; i <= rtn; i++) UpdateBucket(i);
}
void Delete(int tx){
	int b,i;
	for (b = 0; b <= rtn; b++)
		if (e[b].sz && tx <= e[b].x[e[b].sz - 1]) break;
	if(b==rtn+1) b--;
	for (i = 0; e[b].x[i] != tx; i++);
	e[b].sz--;
	for (; i<e[b].sz; i++) e[b].x[i] = e[b].x[i + 1];
	UpdateBucket(b);
}
void Add(int tx){
	int b;
	for (b = 0; b <= rtn; b++)
		if (e[b].sz && tx <= e[b].x[e[b].sz - 1]) break;
	if (b == rtn + 1) b--;
	for (int i = 0; i < e[b].sz; i++)
		if (e[b].x[i]>tx) swap(e[b].x[i], tx);
	e[b].x[e[b].sz++] = tx;
	UpdateBucket(b);
}
int ucnt;
int update(int i, int y){
	if (ucnt++%rtn == 0) Restructure();
	Delete(x[i]);
	Add(x[i] = y);
	int ans = 0, b=-1, tx=-1, t;
	while (++b <= rtn){
		t = upper_bound(e[b].x, e[b].x + e[b].sz, tx) - e[b].x;
		if (t == e[b].sz) continue;
		ans += e[b].cnt[t];
		tx = e[b].d[t] + l;
	}
	return ans;
}

Compilation message (stderr)

elephants.cpp: In function ‘void init(int, int, int*)’:
elephants.cpp:14:14: error: ‘sqrt’ was not declared in this scope
  rtn = sqrt(N);
              ^