Cod sursa(job #1498783)

Utilizator robx12lnLinca Robert robx12ln Data 9 octombrie 2015 10:02:05
Problema Arbori de intervale Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.29 kb
#include<fstream>
#define DIM 100005
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int A[DIM],v[DIM],op,i,m,n,p,x,maxim;
void build(int nod,int st,int dr){
    if(st==dr){
        A[nod]=v[st];
    }else{
        int mid=(st+dr)/2;
        build(2*nod,st,mid);
        build(2*nod+1,mid+1,dr);
        A[nod]=max(A[2*nod],A[2*nod+1]);
    }
    return;
}
void update(int nod,int st,int dr,int p,int x){
    if(st==dr){
        A[nod]=x;
    }else{
        int mid=(st+dr)/2;
        if(p<=mid)
            update(2*nod,st,mid,p,x);
        if(p>mid)
            update(2*nod+1,mid+1,dr,p,x);
        A[nod]=max(A[2*nod],A[2*nod+1]);
    }
}
void query(int nod,int st,int dr,int a,int b){
    if(a<=st && dr<=b){
        maxim=max(maxim,A[nod]);
    }else{
        int mid=(st+dr)/2;
        if(a<=mid)
            query(2*nod,st,mid,a,b);
        if(b>mid)
            query(2*nod+1,mid+1,dr,a,b);
    }
}
int main(){
    fin>>n>>m;
    for(i=1;i<=n;i++){
        fin>>v[i];
    }
    build(1,1,n);
    for(i=1;i<=m;i++){
        fin>>op>>p>>x;
        if(op==1){
            update(1,1,n,p,x);
        }else{
            maxim=-100000000;
            query(1,1,n,p,x);
            fout<<maxim<<"\n";
        }
    }
    return 0;
}