Cod sursa(job #3364592)

Utilizator TudorMitMituca Tudor TudorMit Data 6 septembrie 2026 15:11:49
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.81 kb
#include <fstream>
using namespace std;

ifstream cin("aib.in");
ofstream cout("aib.out");

int aib[200005],n;

void upd(int pos,int val){
	for(int i=pos;i<=n;i+=i&-i)
		aib[i]+=val;
}

int qr1(int pos){
	int s=0;
	for(int i=pos;i>0;i-=i&-i)
		s+=aib[i];
	return s;
}

int qr2(int x){
	int s=0,poz=0,p=1;
	while(p*2<=n)
		p*=2;
	for(;p>0;p/=2){
		if(poz+p<=n && s+aib[poz+p]<x){
			s+=aib[poz+p];
			poz+=p;
		}
	}
	if(poz<n && qr1(poz+1)==x)
		return poz+1;
	return -1;
}

int main(){
	int m,op,x,a,b;
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>x;
		upd(i,x);
	}
	for(int i=1;i<=m;i++){
		cin>>op;
		if(op==0){
			cin>>a>>b;
			upd(a,b);
		}
		else if(op==1){
			cin>>a>>b;
			cout<<qr1(b)-qr1(a-1)<<'\n';
		}
		else{
			cin>>a;
			cout<<qr2(a)<<'\n';
		}
	}
	return 0;
}