Cod sursa(job #1729831)

Utilizator FredyLup Lucia Fredy Data 15 iulie 2016 18:05:41
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.45 kb
#include <iostream>
#include <fstream>

using namespace std;

ifstream fin("aib.in");
ofstream fout("aib.out");

#define lim 100001
int n,aib[lim],pos,val,a,b;


int fsum(int pos)
{
    int rez=0;
    for(; pos>=1; pos-=(pos&(-pos)))
        rez+=aib[pos];
    return rez;
}



void aib_add(int pos,int val)
{
    for(; pos<=n; pos+=(pos&(-pos)))
        aib[pos]+=val;
}



int aib_query(int st, int dr)
{
    return fsum(dr)-fsum(st-1);
}




int aib_pozmin(int val)
{
    int step;
    bool ok=0;
    pos=0;
    for(step=1; step<=n; step<<=1);
    for(; step>=1; step>>=1)
        if(pos+step<=n)
            if(fsum(pos+step)<=val)
            {
                pos+=step;
                if(fsum(pos)==val)
                    ok=1;
            }
    if(ok)
        return pos;
    pos=-1;
    return pos;
}





int main()
{
    int m,i,tip,x;
    fin>>n>>m;
    for(i=1; i<=n; i++)
    {
        fin>>x;
        for(int j=i; j<=n; j+=(j&(-j)) )
            aib[j]+=x;
    }

    for(i=1; i<=m; i++)
    {
        fin>>tip;

        if(tip==0)
        {
            fin>>a>>b;
            aib_add(a,b);
        }

        if(tip==1)
        {
            fin>>a>>b;
            fout<<aib_query(a,b)<<'\n';
        }

        if(tip==2)
        {
            fin>>a;
            fout<<aib_pozmin(a)<<'\n';
        }
    }


    fin.close();
    fout.close();
    return 0;
}