Cod sursa(job #172058)

Utilizator mariussMarius Telespan mariuss Data 5 aprilie 2008 18:23:48
Problema Arbori de intervale Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.39 kb
#include<stdio.h>
#define nmax 100005
int v[2*nmax],val[nmax];

inline int MAX(int a, int b)
{
    if (a>=b)
        return a;
    return b;
}

void build(int x,int y, int p)
{
    if(x==y)
    {
        v[p]=val[x];
        return;
    }
    
    int mij=(x+y)>>1;
    
    build(1,mij,p<<1);
    build(mij+1,y,(p<<1)+1);
    
    v[p]=MAX(v[p<<1],v[(p<<1)+1]);
}

int query( int x, int y, int p, int a, int b)
{
    if(a<=x && y<=b)
    {
        return v[p];
    }
    
    int mij=(x+y)>>1,mx=9999;
    
    if(a<=mij)  mx=MAX(mx,query(x,mij,p<<1,a,b));
    if(b<=mij)  mx=MAX(mx,query(mij+1,y,(p<<1)+1,a,b));
    
    return mx;
}

void update(int x, int y, int p, int a, int b)
{
    if(x==y)
    {
        v[p]==b;
        return;
    }
    
    int mij=(x+y)>>1;
    
    if(a<=mij) update(x,mij,p<<1,a,b);
    if(mij+1<=a) update(mij+1,y,(p<<1)+1,a,b);
    
    v[p]=MAX(v[p<<1],v[(p<<1)+1]);
    
}

int main()
{
    int i, j,n,m,a,b,k;
    
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    
    scanf("%d %d",&n,&m);
    
    for(i=1;i<=n;i++)
        scanf("%d",&val[i]);
        
    build(1,n,1);
    
    for(i=1;i<=m;i++)
    {
        scanf("%d %d %d",&k,&a,&b);
        if(k==0)
            printf("%d\n",query(1,n,1,a,b));
        else
            update(1,n,1,a,b);
    }
    
    return 0;
}