Cod sursa(job #2182723)

Utilizator AlexutAlex Calinescu Alexut Data 22 martie 2018 16:45:39
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.37 kb
#include <cstdio>

using namespace std;
int aib[100005];
int n;
void update(int poz,int val)
{
    for(;poz<=n;poz+=(poz&-poz))
        aib[poz]+=val;
}
int query(int poz)
{
    int s=0;
    for(;poz>0;poz-=(poz&-poz))
        s+=aib[poz];
    return s;
}
int sp[100005];
int main()
{
    freopen("aib.in","r",stdin);
    freopen("aib.out","w",stdout);

    int x,p,i,j;
    scanf("%d%d",&n,&p);
    for(i=1;i<=n;i++)
    {
       scanf("%d",&x);
       sp[i]=sp[i-1]+x;
    }
    for(i=1;i<=n;i++)
    {
        aib[i]=sp[i]-sp[i-(i&-i)];
    }
    int y,z;
    for(i=1;i<=p;i++)
    {
        scanf("%d%d",&x,&y);
        if(x==0)
        {
            scanf("%d",&z);
            update(y,z);
        }
        else if(x==1)
        {
            scanf("%d",&z);
            printf("%d\n", query(z)-query(y-1));
        }
        else
        {
         int st=1,dr=n,ok=0;
          while(st<=dr)
          {
            int med=(st+dr)>>1;
            int suma=query(med);
            if(suma==y)
            {
                printf("%d\n",med);
                ok=1;
                break;
            }
            if(suma>y)dr=med-1;
            else
                st=med+1;
          }
          if(ok==0)
          {
            printf("-1\n");
            continue;
          }

        }
    }
    return 0;
}