Cod sursa(job #1348251)

Utilizator cosmin_bobeicaCosmin Bobeica cosmin_bobeica Data 19 februarie 2015 16:33:12
Problema Arbori de intervale Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.39 kb
#include <cstdio>
#include <algorithm>

using namespace std;

int aint[100001];
int ans,n,m;

void update(int nod, int st, int dr, int poz, int val)
{
    int med;
    
    if(st == dr)
    {
        aint[nod] = val;
        return;
    }
    
    med = (st + dr) / 2;
    
    if(poz <= med)
        update(2 * nod, st, med, poz, val);
    else
        update(2 * nod + 1, med + 1, dr, poz, val);
    
    aint[nod] = max(aint [2 * nod], aint[2 * nod + 1]);
}

void query(int nod, int st, int dr, int x, int y)
{
    int med;
    
    if(x <= st && y>= dr)
    {
        ans = max(ans, aint[nod]);
        return;
    }
    
    med = (st + dr) / 2;
    
    if(x <= med)
        query(2 * nod, st, med, x, y);
    
    if(y > med)
        query(2 * nod + 1, med + 1, dr, x, y);
    
}

int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    
    scanf("%d %d", &n, &m);
    
    int val, op, a, b;
    
    for(int i = 1; i <= n; i ++)
    {
        scanf("%d", &val);
        update(1, 1, n, i, val);
    }
    
    for(int i = 1; i <= m; i ++)
    {
        scanf("%d", &op);
        
        if(op == 0)
        {
            scanf("%d %d", &a, &b);
            ans = 0;
            query(1, 1, n, a, b);
            printf("%d\n", ans);
        }
        else
        {
            scanf("%d %d", &a, &b);
            update(1, 1, n, a, b);
        }
    }
    
    return 0;
}