Cod sursa(job #1638317)

Utilizator alexmisto342Turdean Alexandru alexmisto342 Data 7 martie 2016 22:29:32
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.1 kb
#include <fstream>
#include <cstring>
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int n,i,j,m,x,y,a,b,k,v[100005];
void update(int poz, int val)
{
    int i;
    for(i = poz; i <= n; i+=(-i)&i)
        v[i] += val;
}
int suma(int poz)
{
    int i;
    b = 0;
    for(i = poz; i>0 ; i-=(-i)&i)
        b += v[i];
    return b;
}
int find( int x )
{
    int i,step;
    for( step = 1 ; step <= n ; step <<= 1);
    for( i = 0 ; step ; step>>=1 )
    {
        if( i + step <= n && v[ i + step ] <= x )
        {
            x -= v[ i + step ];
            i += step;
            if( x == 0 )
                return i;
        }
    }
    return -1;
}
int main()
{
    fin >> n >> m;
    for(i = 1; i <= n; i++)
        fin >> a,update(i, a);
    for(i = 1 ;i <= m; i++)
    {
        int p;
        fin >> p;
        if(p == 0)
            fin >> a >> b,update(a,b);
        else
            if(p == 1)
                fin >> a >> b,fout<<suma(b) - suma(a-1)<<"\n";
            else
                fin>>a,fout<<find(a)<<'\n';
    }
    return 0;
}