# Cod sursa(job #143961)

Utilizator Data 26 februarie 2008 23:13:48 Arbori de intervale Ascuns cpp done 1.66 kb
``````#include <stdio.h>
#include <fstream>
#include <assert.h>
using namespace std;

#define in "arbint.in"
#define out "arbint.out"
#define dim 100001

int N, M;
int MaxArb[4*dim+66];
int start, finish, Val, Pos, maxim;

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

void Update(int,int,int);
void Query(int,int,int);

int main()
{
int X, A, B;
freopen(in,"r",stdin);
freopen(out,"w",stdout);

scanf("%d%d", &N, &M);
for ( int i = 1; i <= N; i++ )
{
scanf("%d", &X);
Pos = i, Val = X;
Update(1,1,N);
}

for ( int i = 1; i <= M; i++ )
{
scanf("%d%d%d", &X, &A, &B);
if ( X == 0 )
{
maxim = -1;
start = A, finish = B;
Query(1,1,N);

printf("%d\n", maxim);
}
else
{
Pos = A, Val = B;
Update(1,1,N);
}
}
}

void Update(int nod, int left, int right)
{
if ( left == right )
{
MaxArb[nod] = Val;
return;
}

int div = (left+right)/2;
if ( Pos <= div ) Update(2*nod,left,div);
else              Update(2*nod+1,div+1,right);

MaxArb[nod] = Maxim( MaxArb[2*nod], MaxArb[2*nod+1] );
}

void Query(int nod, int left, int right)
{
if ( start <= left && right <= finish )
{
if ( maxim < MaxArb[nod] ) maxim = MaxArb[nod];
return;
}

int div = (left+right)/2;
if ( start <= div ) Query(2*nod,left,div);
if ( div < finish ) Query(2*nod+1,div+1,right);
}
``````