Cod sursa(job #1074959)

Utilizator alecsandrualex cuturela alecsandru Data 8 ianuarie 2014 11:20:12
Problema Arbori indexati binar Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.27 kb
#include<cstdio>
using namespace std;
int aib[100001],n,m,i,a,b;
int query(int p)
{
    int s=0;
    while(p!=0)
    {
        s+=aib[p];
        p-=p&(-p);
    }
    return s;
}
void update(int p,int val)
{
    while(p<=n)
    {
        aib[p]+=val;
        p+=p&(-p);
    }
}
void bs(int rez)
{
    int st=1,dr=n,med,q;
    while(st<=dr)
    {
        med=((dr-st)>>1)+st;
        q=query(med);
        if(q==rez)
        {
            printf("%d\n",med);
            return;
        }
        if(q<rez)
        {
            st=med+1;
        }
        else
        {
            dr=med-1;
        }
    }
}
int main()
{
    int x;
    freopen("aib.in","r",stdin);
    freopen("aib.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(i=1;i<=n;i++)
    {
        scanf("%d",&x);
        update(i,x);
    }
    for(i=1;i<=m;i++)
    {
        scanf("%d",&x);
        if(x==0)
        {
            scanf("%d%d",&a,&b);
            update(a,b);
        }
        else
            if(x==1)
            {
                scanf("%d%d",&a,&b);
                printf("%d\n",query(b)-query(a-1));
            }
            else
            {
                scanf("%d",&a);
                bs(a);
            }
    }
    return 0;
}