Cod sursa(job #1500007)

Utilizator alexandru.ghergutAlexandru-Gabriel Ghergut alexandru.ghergut Data 11 octombrie 2015 13:54:31
Problema Datorii Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.44 kb
#include <fstream>
#include <cmath>
using namespace std;

void update(int index, int val, int pos, int left, int right, int tree[])
{
    if (left == right && pos == left)
        tree[index] += val;
    else if (pos >= left && pos <= right)
    {
        update(index * 2 + 1, val, pos, left, (left + right) / 2, tree);
        update(index * 2 + 2, val, pos, (left + right) / 2 + 1, right, tree);

        tree[index] += val;
    }
}

int query(int index, int left, int right, int cLeft, int cRight, int tree[])
{
    if (left <= cLeft && right >= cRight)
        return tree[index];

    if (cLeft > right || cRight < left)
        return 0;

    int leftSum = query(index * 2 + 1, left, right, cLeft, (cLeft + cRight) / 2, tree);
    int rightSum = query(index * 2 + 2, left, right, (cLeft + cRight) / 2 + 1, cRight, tree);

    return leftSum + rightSum;
}

int main()
{
    int i, N, M, a;
    ifstream f("datorii.in");
    f >> N >> M;
    int length = (1 << ((int)log2(N) + 2)) - 1;
    int tree[length];
    fill(tree, tree + length, 0);
    for (i = 0; i < N; i++)
    {
        f >> a;
        update(0, a, i, 0, N - 1, tree);
    }

    int op, x, y;
    ofstream g("datorii.out");
    for (i = 0 ; i < M; i++)
    {
        f >> op >> x >> y;
        if (op == 0)
            update(0, -y, x - 1, 0, N - 1, tree);
        else if (op == 1)
            g << query(0, x - 1, y - 1, 0, N - 1, tree) << '\n';
    }
    f.close();
    g.close();
    return 0;
}