Cod sursa(job #2064815)

Utilizator CammieCamelia Lazar Cammie Data 12 noiembrie 2017 20:55:52
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.6 kb
#include <fstream>

#define MAXN 100005

using namespace std;

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

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

inline void build(int poz, int st, int dr) {
    int mij = (st + dr) / 2;

    if (st == dr) {
        ait[poz] = in[st];
        return;
    }
    else {
        build(poz * 2, st, mij);
        build(poz * 2 + 1, mij + 1, dr);
        ait[poz] = max(ait[poz * 2], ait[poz * 2 + 1]);
    }
}

inline int Query(int poz, int st, int dr, int ls, int ld) {
    int mij = (st + dr) / 2;

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

inline void Update(int poz, int st, int dr, int a, int val) {
    int mij = (st + dr) / 2;

    if (st == dr && st == a)
        ait[poz] = val;
    else if (st > a || dr < a)
        return;
    else {
        Update(poz * 2, st, mij, a, val);
        Update(poz * 2 + 1, mij + 1, dr, a, val);

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

inline void Read() {
    int n, m;

    fin >> n >> m;

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

    build(1, 1, n);

    int cer, a, b;

    for (int i = 1; i <= m; i++) {
        fin >> cer >> a >> b;

        if (cer == 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;
}