Cod sursa(job #3304773)

Utilizator Gabriel_DaescuDaescu Gabriel Florin Gabriel_Daescu Data 27 iulie 2025 00:00:44
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 2.05 kb
#include <fstream>
#define NMAX 100002
using namespace std;
ifstream  fin("aib.in");
ofstream fout("aib.out");
int N,M,v[NMAX],aint[4*NMAX];

void citire()
{
    fin>>N>>M;

    for(int i=1; i<=N; i++)
    {
        fin>>v[i];
    }
}

void build(int nod, int st, int dr)
{
    if(st==dr)
    {
        aint[nod]=v[st];
    }
    else
    {
        int pmijl=(st+dr)/2;
        build(2*nod,st,pmijl);
        build(2*nod+1,pmijl+1,dr);

        aint[nod]=aint[2*nod]+aint[2*nod+1];
    }
}

void update(int a, int b, int nod, int st, int dr)
{
    if(st==dr)
    {
        aint[nod]+=b;
    }
    else
    {
        int pmijl=(st+dr)/2;

        if(a<=pmijl)
        {
            update(a,b,2*nod,st,pmijl);
        }
        else
        {
            update(a,b,2*nod+1,pmijl+1,dr);
        }

        aint[nod]=aint[2*nod]+aint[2*nod+1];
    }
}

int query(int a, int b, int nod, int st, int dr)
{
    if(dr<a || st>b)
    {
        return 0;
    }

    if(a<=st && dr<=b)
    {
        return aint[nod];
    }

    int pmijl=(st+dr)/2;
    return query(a,b,2*nod,st,pmijl)+query(a,b,2*nod+1,pmijl+1,dr);
}

int find_k(int a,int nod, int st, int dr)
{
    if(aint[nod]<a)
    {
        return -1;
    }

    if(st==dr)
    {
        if(aint[nod]==a)
        {
            return st;
        }
        else
        {
            return -1;
        }
    }

    int pmijl=(st+dr)/2;
    if(aint[2*nod]>=a)
    {
        return find_k(a,2*nod,st,pmijl);
    }
    else
    {
        return find_k(a-aint[2*nod],2*nod+1,pmijl+1,dr);
    }
}

int main()
{
    citire();

    build(1,1,N);

    for(int q=1; q<=M; q++)
    {
        int op,a,b;
        fin>>op>>a;

        if(op==0)
        {
            fin>>b;
            update(a,b,1,1,N);
        }

        if(op==1)
        {
            fin>>b;
            fout<< query(a,b,1,1,N) << "\n";
        }

        if(op==2)
        {
            fout<< find_k(a,1,1,N) << "\n";
        }
    }

    return 0;
}