Cod sursa(job #2289164)

Utilizator 0738076326Simon Wil 0738076326 Data 24 noiembrie 2018 11:44:18
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.37 kb
#include <bits/stdc++.h>
#define Nmax 100005

using namespace std;

ifstream f("arbint.in");
ofstream g("arbint.out");

int v[Nmax],A[4*Nmax],n,m;
int poz,start,stop;

void build(int l,int r, int node){
    if(l==r){
        A[node]=v[l];
    }
    else{
        int mid=(l+r)/2;
        build(l,mid,2*node);
        build(mid+1, r, 2*node+1);

        A[node]=max(A[2*node], A[2*node+1]);

    }
}

void update(int l, int r, int node){
    if(l==r){
            A[node]=v[l];
    }else{
    int mid=(l+r)/2;
    if(poz<=mid) update(l,mid,2*node);
    else update(mid+1, r, 2*node+1);

      A[node]=max(A[2*node], A[2*node+1]);
    }
}

int query(int l, int r, int node){
    if(start<=l && stop>=r)
    {
        return A[node];
    }else{
    int mid=(l+r)/2;
    int maxl=INT_MIN,maxr=INT_MIN;

    if(start<=mid)
        maxl=query(l,mid,2*node);
    if(mid+1<=stop) maxr=query(mid+1, r, 2*node+1);

    return max(maxl, maxr);
    }
}

int main(){
    f>>n>>m;
    for(int i=1; i<=n; i++)
        f>>v[i];

    build(1,n,1);

    int op, x,y;
    for(int i=1; i<=m; i++){
        f>>op>>x>>y;
        if(op==0)
        {
            start=x;
            stop=y;

            g<<query(1,n,1)<<"\n";
        }
        else{
            v[x]=y;
            poz=x;
            update(1,n,1);
        }
    }

return 0;
}