Cod sursa(job #2666393)

Utilizator unchnounMihai Panduru unchnoun Data 1 noiembrie 2020 18:09:24
Problema Datorii Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.64 kb
// REZOLVARE PRIN ARBORI DE INTERVALE

#include <fstream>
using namespace std;

const int nMax = 15000;
int vec[nMax + 5], aint[4 * nMax + 5];

void build(int k, int left, int right)
{
    if (left == right)
    {
        aint[k] = vec[left];
        return;
    }

    int mid = left + (right - left) / 2;
    build(2 * k, left, mid);
    build(2 * k + 1, mid + 1, right);
    aint[k] = aint[2*k] + aint[2*k+1];
}

void update(int k, int left, int right, int pos, int value)
{
    if (left == right)
    {
        aint[k] -= value;
        return;
    }

    int mid = left + (right - left) / 2;
    if (pos <= mid)
        update(2 * k, left, mid, pos, value);
    else
        update(2 * k + 1, mid + 1, right, pos, value);
    aint[k] = aint[2*k] + aint[2*k+1];
}

int query(int k, int left, int right, int intLeft, int intRight)
{
    if (intLeft <= left && right <= intRight)
        return aint[k];

    int mid = left + (right - left) / 2, retLeft = 0, retRight = 0;
    if (intLeft <= mid)
        retLeft = query(2 * k, left, mid, intLeft, intRight);
    if (intRight >= mid + 1)
        retRight = query(2 * k + 1, mid + 1, right, intLeft, intRight);

    return retLeft + retRight;
}

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

    int n, q;
    fin >> n >> q;
    for (int i = 1; i <= n; ++i)
        fin >> vec[i];
    build(1,1,n);
    for (int i = 1; i <= q; ++i)
    {
        int num, a, b;
        fin >> num >> a >> b;
        if (num == 0)
            update(1,1,n,a,b);
        else if (num == 1)
            fout << query(1,1,n,a,b) << '\n';
    }
}