Cod sursa(job #2381175)

Utilizator BurlacuMateiBurlacu Matei BurlacuMatei Data 16 martie 2019 10:38:58
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.21 kb
#include <bits/stdc++.h>
#define DMAX 400010

using namespace std;

ifstream fin("arbint.in");
ofstream fout("arbint.out");

int V[DMAX];

int n,m;


inline int maxim(int x,int y)
           {if(x>y)
               return x;
            return y;
           }

void update(int node,int pos,int val,int st,int dr);
int query(int node,int st,int dr,int x,int y);

int main()
{int i,val,x,y,t;
 fin>>n>>m;
 for(i=1;i<=n;i++)
     {fin>>val;
      update(1,i,val,1,n);
     }
 for(i=1;i<=m;i++)
     {fin>>t;
      fin>>x>>y;
      if(t)
         update(1,x,y,1,n);
         else
         fout<<query(1,1,n,x,y)<<'\n';
     }

 return 0;
}
void update(int node,int pos,int val,int st,int dr)
{if(st==dr)
    V[node]=val;
    else
    {int mid=(st+dr)/2;
     if(pos<=mid)
        update(2*node,pos,val,st,mid);
        else
        update(2*node+1,pos,val,mid+1,dr);
     V[node]=maxim(V[2*node],V[2*node+1]);
    }
}
int query(int node,int st,int dr,int x,int y)
{int ans_l=0,ans_r=0;
 if(st>=x && dr<=y)
    return V[node];
 int mid=(st+dr)/2;
 if(mid>=x)
    ans_l=query(2*node,st,mid,x,y);
 if(mid<y)
    ans_r=query(2*node+1,mid+1,dr,x,y);
 return maxim(ans_l,ans_r);
}