Cod sursa(job #1914475)

Utilizator FlorinHajaFlorin Gabriel Haja FlorinHaja Data 8 martie 2017 17:06:32
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.18 kb
#include <fstream>

using namespace std;

ifstream f("aib.in");
ofstream g("aib.out");

int arb[100005], n, m, i, j, x, y, t;

void update(int x, int poz) {
    while (poz <= n) {
        arb[poz] += x;
        poz += (poz & -poz);
    }
}

int suma(int poz) {
    int s = 0;
    while (poz > 0) {
        s += arb[poz];
        poz -= (poz & -poz);
    }
    return s;
}

int main() {
    f >> n >> m;
    for (i = 1; i <= n; i++) {
        f >> x;
        update(x, i);
    }
    while (m--) {
        f >> t >> x;
        if (t <2) {
            f>>y;
            if (t==0)
                update(y,x);
            else g << suma(y)-suma(x-1)<<'\n';
        } else {
            int p = 1, k;
            while (p < n) p *= 2;
            for (i = 0; p; p /= 2) {
                if (i+p > n)
                    continue;
                k = suma(i+p);
                if (k == x) {
                    g << i+p << '\n';
                    k = -111;
                    break;
                } else if (k < x)
                    i += p;
            }
            if (k != -111)
                g << "-1\n";
        }
    }
    return 0;
}