Cod sursa(job #900146)

Utilizator the@EyE@Postavaru Stefan the@EyE@ Data 28 februarie 2013 17:54:00
Problema Arbori de intervale Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
#include<cstdio>
#include<algorithm>
#define INF 100001

using namespace std;

int arb[2*INF],n,m;

int maxVal(int nod,int st,int dr,int a,int b)
{
    if(dr<a||st>b)return -1;
    if(st==a&&dr==b)return arb[nod];
    int m=(st+dr)/2;
    return max(maxVal(nod*2,st,m,a,m),maxVal(nod*2+1,m+1,dr,m+1,b));
}

void update(int nod,int st,int dr,int poz,int val)
{
    if(poz<st||poz>dr)return;
    if(st==dr){arb[nod]=val;return;}
    int m=(st+dr)/2;
    if(poz<=m)update(nod*2,st,m,poz,val);
        else update(nod*2+1,m+1,dr,poz,val);

    arb[nod]=max(arb[nod*2],arb[nod*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)
    {
        int x;
        scanf("%d",&x);
        update(1,1,n,i,x);
    }
    for(int i=0;i<m;++i)
    {
        int c,a,b;
        scanf("%d%d%d",&c,&a,&b);
        if(c==0)printf("%d\n",maxVal(1,1,n,a,b));
        else update(1,1,n,a,b);
    }
    return 0;
}