Cod sursa(job #2581361)

Utilizator PetrescuAlexandru Petrescu Petrescu Data 15 martie 2020 00:10:23
Problema Combinari Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.55 kb
#include <bits/stdc++.h>
#define MAX 100000

using namespace std;

int n;
int v[MAX], aib[MAX];

void update(int idx, int val)
{
    while(idx <= n)
    {
        aib[idx] += val;

        idx += (-idx & idx);
    }
}

int query(int idx)
{
    int suma = 0;

    while(idx)
    {
        suma += aib[idx];

        idx -= (-idx & idx);
    }

    return suma;
}

int sumaInterval(int idx1, int idx2)
{
    return query(idx2) - query(idx1 - 1);
}


int findVal(int val)
{
    int st = 1, dr = n;

    while(st <= dr)
    {
        int mij = (st + dr) >> 1;

        int aux = query(mij);

        if(aux == val && query(mij - 1) < val)
            return mij;
        else if(aux < val)
            st = mij + 1;
        else dr = mij - 1;
    }

    return -1;
}

int main()
{
    ifstream fin("aib.in");
    ofstream fout("aib.out");

    ios::sync_with_stdio(false);
    fin.tie(0);
    fout.tie(0);
    srand(time(NULL));

    int m;

    fin >> n >> m;

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

        update(i, v[i]);
    }

    for(int i = 1; i <= m; i++)
    {
        int c;

        fin >> c;

        if(c == 2)
        {
            int a;

            fin >> a;

            fout << findVal(a) << '\n';
        }
        else
        {
            int a, b;

            fin >> a >> b;

            if(c == 0)update(a, b);
            else fout << sumaInterval(a, b) << '\n';
        }
    }

    fin.close();
    fout.close();

    return 0;
}