Cod sursa(job #1037654)

Utilizator ciobu69Ciobanu Sergiu ciobu69 Data 20 noiembrie 2013 16:10:40
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.76 kb
#include<fstream>
#define lsb(x) ((x)&(-x))
using namespace std;
ifstream f("aib.in"); ofstream g("aib.out");
int n,aib[100005];
void update(int p,int val)
{	for(;p<=n;p+=lsb(p)) aib[p]+=val;}
int query(int p)
{	int ans=0;
    for(;p;p-=lsb(p)) ans+=aib[p];
    return ans;
}
int main()
{	int m,x,y,tip,Pmax,i;
	f>>n>>m;
    for(Pmax=1;Pmax<=n;Pmax<<=1);Pmax>>=1;
    for(i=1;i<=n;i++) f>>x, update(i,x);
    while(m--)
    {	f>>tip>>x;
        if(tip==2)
			{	int ans=0;
                for(i=Pmax;i;i>>=1)
                    if(ans+i<n && query(ans+i)<x) ans+=i;
                if(query(ans+1)==x) g<<ans+1<<'\n'; else g<<"-1\n";
			}
		else 
			{	f>>y;
				if(tip) g<<query(y)-query(x-1)<<'\n'; else update(x,y);
			}
    }
    return 0;
}