Cod sursa(job #2739056)

Utilizator ViAlexVisan Alexandru ViAlex Data 6 aprilie 2021 19:07:32
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 kb
#include<iostream>
#include<fstream>
#include<vector>
#include<cstring>
#include<map>
#include<algorithm>
#include<set>
#include<deque>
#include<queue>

using namespace std;
ifstream in("arbint.in");
ofstream out("arbint.out");

const int mx=1e5;

int n,m,v[mx],tree[3*mx];

void read(){
	in>>n>>m;
	for(int i=0;i<n;i++){
		in>>v[i];
	}
}

void build_tree(int index,int l,int r){
	if(l==r){
		tree[index]=v[l];
	}
	else{
		int m=(l+r)/2;
		build_tree(index*2,l,m);
		build_tree(index*2+1,m+1,r);
		tree[index]=max(tree[index*2],tree[index*2+1]);
	}
}

int query(int index,int l,int r,int a,int b){
	if(l>=a && r<=b){
		return tree[index];
	}
	int m=(l+r)/2,result=-1;
	if(a<=m){
		result=max(result,query(index*2,l,m,a,b));
	}
	if(b>m){
		result=max(result,query(index*2+1,m+1,r,a,b));
	}
	return result;
}

void update(int index,int l,int r,int pos,int value){
	if(l==r){
		tree[index]=value;
	}
	else{
		int m=(l+r)/2;
		if(pos<=m){
			update(index*2,l,m,pos,value);
		}
		else{
			update(index*2+1,m+1,r,pos,value);	
		}
		tree[index]=max(tree[index*2],tree[index*2+1]);
	}
}


void solve(){
	int q,l,r;
	build_tree(1,0,n-1);
	while(m--){
		in>>q>>l>>r;
		if(q==0){
			out<<query(1,0,n-1,l-1,r-1)<<'\n';
		}
		else{
			update(1,0,n-1,l-1,r);	
		}
	}
}

int main(){
	read();
	solve();
	return 0;
}