Cod sursa(job #1728179)

Utilizator stelian2000Stelian Chichirim stelian2000 Data 12 iulie 2016 13:36:34
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.22 kb
#include <cstdio>

using namespace std;

int n,v[100010];

void aib_update(int a,int b)
{
    for(int i=a;i<=n;i+=i&(-i)) v[i]+=b;
}

int aib_query(int a)
{
    int s=0;
    for(int i=a;i>=1;i-=i&(-i)) s+=v[i];
    return s;
}

int main()
{
    freopen("aib.in","r",stdin);
    freopen("aib.out","w",stdout);
    int m,a,op,b,logn=0,poz;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&a);
        aib_update(i,a);
    }
    for(logn=1;(1<<logn)<=n;logn++);
    logn--;
    for(int t=1;t<=m;t++)
    {
        scanf("%d",&op);
        if(op==0)
        {
            scanf("%d%d",&a,&b);
            aib_update(a,b);
        }
        if(op==1)
        {
            scanf("%d%d",&a,&b);
            printf("%d\n",aib_query(b)-aib_query(a-1));
        }
        if(op==2)
        {
            scanf("%d",&a);
            int poz=0,s=a;
            for(int i=logn;i>=0;i--)
                if(poz+(1<<i)<=n && v[poz+(1<<i)]<a)
                {
                    poz+=1<<i;
                    a-=v[poz];
                }
            poz++;
            if(aib_query(poz)==s) printf("%d\n",poz);
            else printf("-1\n");
        }
    }
    return 0;
}