Cod sursa(job #2154441)

Utilizator andra_moldovanAndra Moldovan andra_moldovan Data 6 martie 2018 22:45:58
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.3 kb
#include <fstream>

#define MAXN 100005

using namespace std;

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

int ait[MAXN * 4];

inline void Update(int poz, int st, int dr, int p, int val) {
    if (st == dr && st == p) {
        ait[poz] = val;
        return;
    }

    if (p < st || p > dr)
        return;

    int mij = (st + dr) / 2;

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

    ait[poz] = max(ait[poz * 2], ait[poz * 2 + 1]);
}

inline 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 max(aux1, aux2);
}

inline void Read() {
    int N, M, val, tip, a, b;

    fin >> N >> M;

    for (int i = 1; i <= N; i++) {
        fin >> val;;

        Update(1, 1, N, i, val);
    }

    while (M--) {
        fin >> tip >> a >> b;

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

int main () {
    Read();

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