Cod sursa(job #911944)

Utilizator TeodoraTanaseTeodora Tanase TeodoraTanase Data 11 martie 2013 23:00:34
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.36 kb
#include <cstdio>
#include <algorithm>

#define NMAX 4 * 100001

using namespace std;

int n;
int H[NMAX];

void add(int val, int nod, int st, int dr, int poz)
{
    if(st == dr)
    {
        H[nod] = val;
        return;
    }

    int mij = (st + dr) >> 1;
    int fiu = nod << 1;

    if(poz <= mij)
        add(val, fiu, st, mij, poz);
    else
        add(val, fiu + 1, mij + 1, dr, poz);

    H[nod] = max(H[fiu], H[fiu + 1]);
}

int read()
{
    int m;
    int x;

    freopen("arbint.in", "r", stdin);

    scanf("%d %d\n", &n, &m);

    for(int i = 1; i <= n; ++ i)
    {
        scanf("%d ", &x);
        add(x, 1, 1, n, i);
    }

    return m;
}

int solve(int a, int b, int nod, int st, int dr)
{
    if(a <= st && dr <= b)
        return H[nod];

    int mij = (st + dr) >> 1;
    int fiu = nod << 1;

    int xa = -1;
    int xb = -1;

    if(a <= mij)
        xa = solve(a, b, fiu, st, mij);
    if(b > mij)
        xb = solve(a, b, fiu + 1, mij + 1, dr);

    return max(xa, xb);
}

int main()
{
    freopen("arbint.out", "w", stdout);

    int a;
    int b;
    int c;
    int m = read();

    while(m --)
    {
        scanf("%d %d %d\n", &c, &a, &b);

        if(c == 1)
            add(b, 1, 1, n, a);
        else
            printf("%d\n", solve(a, b, 1, 1, n));
    }

    return 0;
}