Cod sursa(job #522542)

Utilizator andy_vamosRezus Andrei andy_vamos Data 15 ianuarie 2011 14:24:04
Problema Cautare binara Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include<fstream>
using namespace std;
int n,a[100001],m,x,y,i;
int bin_search0(int st,int dr,int x)
{
	int mij;
	while(st<=dr)
	{
		mij=(st+dr)/2;
		if(a[mij]<=x) 
			st=mij+1;	
		else 
			dr=mij-1;
	}
	mij=(st+dr)/2;
	if(a[mij]>x)
		mij--;
	if(a[mij]==x)
		return mij;
	else
		return -1;	
}
int bin_search1(int st,int dr,int x)
{
	int mij;
	while(st<dr)
	{
		mij=(st+dr)/2;
		if(a[mij]<=x)
			st=mij+1;
		else 
			dr=mij;
	}
	mij=(st+dr)/2;
	if(a[mij]>x)
		mij--;
	return mij;
}
int bin_search2(int st,int dr,int x)
{
	int mij;
	while(st<dr)
	{
		mij=(st+dr)/2;
		if(a[mij]>=x)
			dr=mij;
		else 
			st=mij+1;
	}
	mij=(st+dr)/2;
	if(a[mij]<x)
		mij++;
	return mij;
}
int main()
{
	ifstream f("cbinara.in");
	ofstream g("cbinara.out");
	f>>n;
	for(i=1;i<=n;i++)
		f>>a[i];
	f>>m;
	for(i=1;i<=m;i++)
	{
		f>>x>>y;
		if(y==0)
			g<<bin_search0(1,n,x)<<"\n";
		else 
		if(y==1)
			g<<bin_search1(1,n,x)<<"\n";
		else
		if(y==2)
			g<<bin_search2(1,n,x)<<"\n"; 
	}
	return 0;
}