Cod sursa(job #469557)

Utilizator dushmiMihai-Alexandru Dusmanu dushmi Data 8 iulie 2010 12:03:25
Problema Arbori indexati binar Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.3 kb
#include<cstdio>
#define N 1<<17
int n,m,v[N];
int bit(int x)
{
    return ((x&(x-1))^x);
}
void update(int poz,int x)
{
    while(poz<=n)
    {
        v[poz]+=x;
        poz+=bit(poz);
    }
}
unsigned int suma(int poz)
{
    unsigned int s=0;
    while(poz)
    {
        s+=v[poz];
        poz-=bit(poz);
    }
    return s;
}
void cautb(unsigned int x)
{
    int i,poz=0;
    for(i=1<<20;i;i>>=1)
    {
        if(poz+i>n)
            continue;
        poz+=i;
        unsigned int s=suma(poz);
        if(s==x)
        {
            printf("%d\n",poz);
            return;
        }
        if(s<x)
            continue;
        poz-=i;
    }
}
int main()
{
    freopen("aib.in","r",stdin);
    freopen("aib.out","w",stdout);
    scanf("%d%d",&n,&m);
    int x,y,t;
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&x);
        update(i,x);
    }
    for(int i=1;i<=m;i++)
    {
        scanf("%d",&t);
        if(t==0)
        {
            scanf("%d%d",&x,&y);
            update(x,y);
        }
        else if(t==1)
        {
            scanf("%d%d",&x,&y);
            printf("%d\n",(unsigned int)suma(y)-suma(x-1));
        }
        else if(t==2)
        {
            scanf("%d",&x);
            cautb(x);
        }
    }
    return 0;
}