Cod sursa(job #2509725)

Utilizator ioanavasi16Vasile Ioana ioanavasi16 Data 14 decembrie 2019 17:35:29
Problema Arbori indexati binar Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.05 kb
#include <fstream>
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int aib[100005],N,M,a,x,y,p,b,st,dr,c,pos;
void update(int x,int pos)
{
    for(int i=pos;i<=N;i+=(i&(-i)))
        aib[i]+=x;
}
int suma(int pos)
{
    int s=0;
    for(int i=pos;i>0;i--)
        s+=aib[i];
    return s;
}
int verificare(int a)
{
    int st=1,dr=N;
    while(st<=dr)
    {
        int mijl=(st+dr)/2;
        if(suma(mijl)==a) return mijl;
        if(suma(mijl)<a) st=mijl+1;
        if(suma(mijl)>a) dr=mijl-1;
    }
    return -1;
}
int main()
{
    fin>>N>>M;
    for(int i=1;i<=N;i++)
    {
        fin>>p;
        update(p,i);
    }
    for(int i=1;i<=M;i++)
    {
        fin>>c;
        if(c==0)
        {
            fin>>a>>b;
            update(b,a);
        }
        else if (c==1)
        {
            fin>>a>>b;
            fout<<suma(b)-suma(a-1)<<"\n";
        }
        else if(c==2)
        {
            fin>>a;
            fout<<verificare(a)<<"\n";
        }
    }

    return 0;
}