Cod sursa(job #351010)

Utilizator SheepBOYFelix Liviu SheepBOY Data 26 septembrie 2009 14:56:17
Problema Range minimum query Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.75 kb
#include<stdio.h>
#include<math.h>
#define MAXN 100000 
int rq[10000][10000],v[MAXN];
int rmq_preprocess(int n)
{
	int i,j;
	for(i=0;i<n;++i)
		rq[i][0]=i;
	for(j=1;j<<1<=n;++j)
		for(i=0;i+(1<<j)-1<n;++i)
			if(v[rq[i][j-1]]<v[rq[i+(1<<(j-1))][j-1]])
				rq[i][j]=rq[i][j-1];
			else
				rq[i][j]=rq[i+(1<<(j-1))][j-1];
}
int rmq(int i,int j)
{
	int k=(int)log((j-i+1>0)?j-i+1:i-j+1);
	return (v[rq[i][k]]<v[rq[j-(1<<k)+1][k]])?v[rq[i][k]]:v[rq[j-(1<<k)+1][k]];
}
int main()
{
	int n=0,q=0,x,y;
	freopen("rmq.in","r",stdin);
	freopen("rmq.out","w",stdout);
	scanf("%d%d",&n,&q);
	for(int i=0;i<n;++i)
		scanf("%d",v+i);
	
	rmq_preprocess(n);
	
	while(q)
	{
		scanf("%d%d",&x,&y);
		printf("%d\n",rmq(x-1,y-1));
		--q;
	}
	return 0;
}