Cod sursa(job #637882)

Utilizator costin7856Antonesi Florean Costin costin7856 Data 20 noiembrie 2011 17:19:38
Problema Cautare binara Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include <fstream>
using namespace std;
int n,a[100001],m,x,y;
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("cautbin.in");
	ofstream g("cautbin.out");
	f>>n;
	for(int i=1;i<=n;++i)
		f>>a[i];
	f>>m;
	for(int i=1;i<=m;++i)
	{
		f>>y>>x;
		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;
}