Cod sursa(job #667625)

Utilizator loredanacosteaCostea Loredana loredanacostea Data 23 ianuarie 2012 15:31:24
Problema Cautare binara Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 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]<mij)
			++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";
		if(y==1)
			g<<bin_search1(1,n,x)<<"\n";
		if(y==2)
			g<<bin_search2(1,n,x)<<"\n";
		}
		return 0;
	}