Cod sursa(job #2509299)

Utilizator GhitzarinoGhita Alexandru Ghitzarino Data 14 decembrie 2019 09:32:13
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.92 kb
#include <fstream>
using namespace std;
ifstream f("aib.in");
ofstream g("aib.out");
int n,m,aib[100001],i,x,c,a,b;
void upd(int x,int p)
{
    int i;
    for(i=p;i<=n;i+=(i&(-i)))
        aib[i]+=x;
}
int sum(int p)
{
    int i,s=0;
    for(i=p;i>0;i-=(i&(-i)))
        s+=aib[i];
    return s;
}
int cauta(int x)
{
    int st=1,dr=n,mij;
    while(st<=dr)
    {
        mij=(st+dr)/2;
        if(sum(mij)==x) return mij;
        else if(sum(mij)<x) st=mij+1;
                else dr=mij-1;
    }
    return -1;
}
int main()
{
    f>>n>>m;
    for(i=1;i<=n;i++)
    {
        f>>x;
        upd(x,i);
    }
    for(i=1;i<=m;i++)
    {
        f>>c;
        if(c==0) {f>>a>>b; upd(b,a);}
        else if(c==1) { f>>a>>b; g<<sum(b)-sum(a-1)<<'\n';}
                else
                    {
                        f>>a;
                        g<<cauta(a)<<'\n';
                    }
    }
}