Cod sursa(job #2952865)

Utilizator denissavaSava Denis denissava Data 10 decembrie 2022 09:29:32
Problema Arbori indexati binar Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.05 kb
#include <fstream>
using namespace std;
#define Ub(x) (x&-x)
#define nmax 150005
ifstream fin("aib.in");
ofstream fout("aib.out");
int Aib[nmax];
int n,i,m,a,c,x,y;
void add(int poz, int val)
{
    int i;
    for(i=poz; i<=n; i+=Ub(i))
        Aib[i]+=val;
}
int suma(int poz)
{
    int s=0,i;
    for(i=poz; i>=1; i-=Ub(i))
        s+=Aib[i];
    return s;
}
int cb(int a)
{
    int st=1,dr=n,poz=-1,mid,s;
    while(st<=dr && poz==-1)
    {
        mid=(st+dr)/2;
        s=suma(mid);
        if(s==a)
            poz=mid;
        else if(s<a)
            st=mid+1;
        else dr=mid-1;
    }
    return poz;
}
int main()
{
    fin>>n>>m;
    for(i=1; i<=n; i++)
    {
        fin>>a;
        add(i,a);
    }
    for(i=1; i<=m; i++)
    {
        fin>>c;
        fin>>x;
        if(c!=2)
        {
            fin>>y;
            if(c==0)
                add(x,y);
            else fout<<suma(y)-suma(x-1)<<endl;
        }
        else
        {
            fout<<cb(x)<<endl;
        }
    }

    return 0;
}