Cod sursa(job #1145575)

Utilizator alex_bucevschiBucevschi Alexandru alex_bucevschi Data 18 martie 2014 12:05:51
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.18 kb
#include <cstdio>

using namespace std;
int n,m,i,cod,x,y,lo,hi,mi,bit,query(int),AIB[100010];
void upd(int,int);
int main()
{
    freopen("aib.in","r",stdin);
    freopen("aib.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(i=1;i<=n;i++)
    {
        scanf("%d",&x);
        upd(i,x);
    }
    for(;m;m--)
    {
        scanf("%d%d",&cod,&x);
        if(cod==0)
        {
            scanf("%d",&y);
            upd(x,y);
            continue;
        }
        if(cod==1)
        {
            scanf("%d",&y);
            printf("%d\n",query(y)-query(x-1));
            continue;
        }
        lo=0;hi=n+1;
        for(;hi-lo-1;)
        {
            mi=(lo+hi)/2;
            if(query(mi)<x)lo=mi;
            else hi=mi;
        }
        if(hi==n+1)printf("-1\n");
        else if(query(hi)==x)printf("%d\n",hi);
        else printf("-1\n");
    }
    return 0;
}
void upd(int poz,int val)
{
    for(;poz<=n;)
    {
        bit=poz&(-poz);
        AIB[poz]+=val;
        poz+=bit;
    }
}
int query(int poz)
{
    int ret=0;
    for(;poz;)
    {
        bit=poz&(-poz);
        ret+=AIB[poz];
        poz-=bit;
    }
    return ret;
}