Cod sursa(job #371714)

Utilizator Bogdan_tmmTirca Bogdan Bogdan_tmm Data 6 decembrie 2009 13:13:22
Problema Arbori indexati binar Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.09 kb
#include<stdio.h>
#include<vector>
using namespace std;
int n,m;
vector <int> aib(100001);
void Update(int ind,int val)
{
	int poz=0;
	do
	{
		aib[ind]+=val;
		while(!(ind&(1<<poz)))
			poz++;
		ind+=(1<<poz);
		poz++;
	}while(ind<=n);
}
int GetSum(int ind)
{
	int poz=0,sum=0;
	do
	{
		sum+=aib[ind];
		while(!(ind&(1<<poz)))
			poz++;
		ind-=(1<<poz);
		poz++;
	}while(0<ind);
	return sum;
}
int PozMin(int sum)
{
	int i,step;
	for(step=1;step<n;step<<=1);
	for(i=0;step;step>>=1)
		if(i+step<=n)
		{
			if(aib[i+step]<=sum)
			{
				i+=step;
				sum-=aib[i];
				if(!sum)
					return i;
			}
		}
	return -1;
}
int main()
{
	freopen("aib.in","r",stdin);
	freopen("aib.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++)
	{
		int x;
		scanf("%d",&x);
		Update(i,x);
	}
	for(;m;m--)
	{
		int x,y,z;
		scanf("%d",&x);
		if(x<2)
		{
			scanf("%d%d",&y,&z);
			if(x==0)
			{
				Update(y,z);
			}
			else
				printf("%d\n",GetSum(z)-GetSum(y-1));
			continue;
		}
		scanf("%d",&y);
		printf("%d\n",PozMin(y));
	}
	return 0;
}