Cod sursa(job #2346358)

Utilizator MarinPeptenaruMarin Vasile Peptenaru MarinPeptenaru Data 17 februarie 2019 16:16:49
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.25 kb
#include <bits/stdc++.h>
#define lsb(x) (-x)&x

using namespace std;
ifstream in("aib.in");
ofstream out("aib.out");
vector < int > aib;
int n,q,x,op,a,b;
void add(int poz, int val)
{
    for(int i=poz; i<=n; i+=lsb(i))
        aib[i]+=val;
}
int get_sum(int poz)
{
    int sum = 0;
    for(int i=poz; i>0; i-=lsb(i))
        sum+=aib[i];
    return sum;
}
int cbin(int val)
{
    int st = 1;
    int dr = n;
    int mij;
    int poz = -1;
    int suma;
    while(st<=dr)
    {
        mij = (st+dr)>>1;
        suma = get_sum(mij);
        if(suma==val)
        {
            dr = mij - 1;
            poz = mij;
        }
        else if(suma<val)
            st = mij + 1;
        else
            dr = mij - 1;
    }
    return poz;
}
int main()
{
    in>>n>>q;
    aib = vector < int > (n+1,0);
    for(int i=1; i<=n; i++)
    {
        in>>x;
        add(i,x);
    }
    for(;q;q--)
    {
        in>>op;
        if(op==0)
        {
            in>>a>>b;
            add(a,b);
        }
        else if(op==1)
        {
            in>>a>>b;
            out<<get_sum(b)-get_sum(a-1)<<'\n';
        }
        else
        {
            in>>a;
            out<<cbin(a)<<'\n';
        }
    }
    return 0;
}