Cod sursa(job #1413263)

Utilizator gapdanPopescu George gapdan Data 1 aprilie 2015 19:24:05
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.28 kb
#include <cstdio>
#define max(a,b) (a > b ? a : b)
#define NMAX 100005

using namespace std;

int v[NMAX],A[NMAX*2];
int n,m,x,y,Max,t;

void update(int st, int dr, int poz, int niv)
{
    if (st == dr)
    {
        A[niv] = v[poz];
        return;
    }
    int mij = (st + dr) / 2;
    if (poz <= mij) update(st,mij,poz,niv*2);
        else update(mij+1,dr,poz,niv*2+1);
    A[niv]=max(A[niv*2],A[niv*2+1]);
}

void query(int st, int dr, int x, int y, int niv)
{
    if (x <= st && dr <= y)
    {
        if (Max < A[niv])  Max = A[niv];
        return;
    }
    int mij = (st+dr)/2;
    if (x <= mij) query(st,mij,x,y,niv*2);
    if (mij < y) query(mij+1,dr,x,y,niv*2+1);
}

int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(int i = 1; i <= n; ++i)
    {
        scanf("%d",&v[i]);
        update(1,n,i,1);
    }
    for(int i = 1; i <= m; ++i)
    {
        scanf("%d",&t);
        if (t == 0)
        {
            scanf("%d%d",&x,&y);
            Max = 0;
            query(1,n,x,y,1);
            printf("%d\n",Max);
        }
        else
        {
            scanf("%d%d",&x,&y);
            v[x]=y;
            update(1,n,x,1);
        }
    }
    return 0;
}