Cod sursa(job #2902721)

Utilizator popescumateicalinPopescu Matei Calin popescumateicalin Data 16 mai 2022 19:14:20
Problema Datorii Scor 60
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.49 kb
#include <fstream>

std::ifstream cin("datorii.in");
std::ofstream cout("datorii.out");

const int MAXN = 15001;
int arr[MAXN], tree[4 * MAXN], n, m, i, x, y, op;

void buildTree(int left, int right, int pos)
{
    if (left == right)
    {
        tree[pos] = arr[left];
        return;
    }
    int mid = left + (right - left) / 2;
    buildTree(left, mid, 2 * pos);
    buildTree(mid + 1, right, 2 * pos + 1);
    tree[pos] = tree[2 * pos] + tree[2 * pos + 1];
}

void updateTree(int left, int right, int pos)
{
    if (left == right)
    {
        tree[pos] = arr[i];
        return;
    }
    int mid = left + (right - left) / 2;
    if (i <= mid)
        updateTree(left, mid, 2 * pos);
    else
        updateTree(mid + 1, right, 2 * pos + 1);
    tree[pos] = tree[2 * pos] + tree[2 * pos + 1];
}

int sumTree(int left, int right, int pos)
{
    if (x <= left && y >= right)
        return tree[pos];
    if (x > right || y < left)
        return 0;
    int mid = left + (right - left) / 2;
    return sumTree(left, mid, 2 * pos) + sumTree(mid + 1, right, 2 * pos + 1);
}

int main()
{
    cin >> n >> m;
    for (i = 1; i <= n; i++)
        cin >> arr[i];
    buildTree(1, n, 1);
    for (int j = 1; j <= m; j++)
    {
        cin >> op >> x >> y;
        if (op == 1)
            cout << sumTree(1, n, 1) << '\n';
        if (op == 0)
        {
            i = x;
            arr[i] -= y;
            updateTree(1, n, 1);
        }
    }
    return 0;
}