Cod sursa(job #603777)

Utilizator nervousNervous nervous Data 18 iulie 2011 17:09:55
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.17 kb
#include <fstream>
#include <cstring>

#define X1 262145

using namespace std;

ifstream in;
ofstream out;

int v[X1];

inline void update(int nod,int L,int R,int pos,int val)
{
    if(L==R&&L==pos) v[nod]=val;
    else
    {
        int M=(L+R)/2;
        if(pos<=M) update(2*nod,L,M,pos,val);
        else update(2*nod+1,M+1,R,pos,val);

        if(v[2*nod]>v[2*nod+1]) v[nod]=v[2*nod];
        else v[nod]=v[2*nod+1];
    }
}

inline int query(int nod,int L,int R,int a,int b)
{
    if(a<=L&&R<=b) return v[nod];
    else
    {
        int M=(L+R)/2,max1=0,max2=0;
        if(a<=M) max1=query(2*nod,L,M,a,b);
        if(b>M) max2=query(2*nod+1,M+1,R,a,b);
        if(max1>max2) return max1;
        else return max2;
    }
}

int main()
{
    int N,M,a,b,tip;

    memset(v,0,sizeof(v));

    in.open("arbint.in");

    in>>N>>M;
    for(int i=1;i<=N;++i)
    {
        in>>a;
        update(1,1,N,i,a);
    }

    out.open("arbint.out");

    for(;M;--M)
    {
        in>>tip>>a>>b;
        if(tip==0) out<<query(1,1,N,a,b)<<'\n';
        else update(1,1,N,a,b);
    }

    in.close();
    out.close();

    return 0;
}