Cod sursa(job #1075970)

Utilizator chiriacandrei25Chiriac Andrei chiriacandrei25 Data 9 ianuarie 2014 19:42:44
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.42 kb
#include <cstdio>
#include <algorithm>
#define Nmax 100005

using namespace std;

int a[4*Nmax],v[Nmax];

inline void Build(int nod, int st, int dr)
{
    if(st==dr)
    {
        a[nod]=v[st];
        return ;
    }
    int mij=(st+dr)/2;
    Build(nod*2,st,mij);
    Build(nod*2+1,mij+1,dr);
    a[nod]=max(a[nod*2],a[nod*2+1]);
}

inline void Update(int nod, int st, int dr, int poz, int val)
{
    if(st==dr)
    {
        a[nod]=val;
        return ;
    }
    int mij=(st+dr)/2;
    if(poz<=mij)
        Update(2*nod,st,mij,poz,val);
    else
        Update(2*nod+1,mij+1,dr,poz,val);
    a[nod]=max(a[2*nod],a[2*nod+1]);
}

inline int Query(int nod, int st, int dr, int x, int y)
{
    if(st==x && y==dr)
        return a[nod];
    int mij=(st+dr)/2;
    if(y<=mij)
        return Query(2*nod,st,mij,x,y);
    else
        if(x>mij)
            return Query(2*nod+1,mij+1,dr,x,y);
        else
            return max(Query(nod*2,st,mij,x,mij), Query(nod*2+1,mij+1,dr,mij+1,y));
}

int main()
{
    int i,tip,x,y,M,N;
    freopen ("arbint.in","r",stdin);
    freopen ("arbint.out","w",stdout);
    scanf("%d%d", &N,&M);
    for(i=1;i<=N;++i)
        scanf("%d", &v[i]);
    Build(1,1,N);
    while(M--)
    {
        scanf("%d%d%d", &tip,&x,&y);
        if(!tip)
            printf("%d\n", Query(1,1,N,x,y));
        else
            Update(1,1,N,x,y);
    }
    return 0;
}