Cod sursa(job #2145406)

Utilizator CammieCamelia Lazar Cammie Data 27 februarie 2018 12:39:25
Problema Datorii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.55 kb
#include <fstream>

#define MAXN 20005

using namespace std;

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

int v[MAXN], ait[MAXN * 4];

inline void Build(int poz, int st, int dr) {
    if (st == dr) {
        ait[poz] = v[st];
        return;
    }
    int mij = (st + dr) / 2;

    Build(poz * 2, st, mij);
    Build(poz * 2 + 1, mij + 1, dr);

    ait[poz] = ait[poz * 2] + ait[poz * 2 + 1];
}

inline void Update(int poz, int st, int dr, int p, int val) {
    if (st == dr && st == p) {
        ait[poz] -= val;
        return;
    }
    if (st > p || dr < p)
        return;
    int mij = (st + dr) / 2;

    Update(poz * 2, st, mij, p, val);
    Update(poz * 2 + 1, mij + 1, dr, p, val);

    ait[poz] = ait[poz * 2] + ait[poz * 2 + 1];
}

int Query(int poz, int st, int dr, int ls, int ld) {
    if (ls <= st && dr <= ld) {
        return ait[poz];
    }
    if (st > ld || dr < ls)
        return 0;
    int mij = (st + dr) / 2;
    int aux1 = Query(poz * 2, st, mij, ls, ld);
    int aux2 = Query(poz * 2 + 1, mij + 1, dr, ls, ld);

    return aux1 + aux2;
}

inline void Read() {
    int N, M, tip, x, y;

    fin >> N >> M;

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

    Build(1, 1, N);

    while (M--) {
        fin >> tip >> x >> y;

        if (tip == 0) {
            Update(1, 1, N, x, y);
        }
        else {
            fout << Query(1, 1, N, x, y) << "\n";
        }
    }
}

int main () {
    Read();

    fin.close(); fout.close(); return 0;
}