Cod sursa(job #427646)

Utilizator hendrikHendrik Lai hendrik Data 28 martie 2010 11:32:50
Problema Arbori de intervale Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.17 kb
#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
using namespace std;

void open(){
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
}

#define MAXN 100010
const int oo=(int)1e9;
int n,m,type,a,b,arr[MAXN],tree[5*MAXN];

void build(int N,int l,int r){
    if (b<l || a>r) return;
    if (l==r){
        tree[N]=arr[l];
        return ;
    }
    int mid=(l+r)>>1;
    build((N<<1),l,mid);
    build((N<<1)|1,mid+1,r);
    tree[N]=max(tree[(N<<1)],tree[(N<<1)|1]);
}

int ask(int N,int l,int r){
    if (a<=l && r<=b) return tree[N];
    if (b<l || a>r) return -oo;
    int mid=(l+r)>>1;
    int k1=ask((N<<1),l,mid);
    int k2=ask((N<<1)|1,mid+1,r);
    return max(k1,k2);
}

int main(){
    open();
    scanf("%d%d",&n,&m);
    for (int i=1;i<=n;i++){
        scanf("%d",&arr[i]);
    }
    a=1;b=n;
    build(1,1,n);
    for (int i=0;i<m;i++){
        scanf("%d%d%d",&type,&a,&b);
        if (type==1){
            arr[a]=b;
            a=b;
            build(1,1,n);
        }
        else {
            printf("%d\n",ask(1,1,n));
        }
    }
    //system("pause");
    return 0;
}