Cod sursa(job #2632820)

Utilizator AlexMariMarinescu Alexandru AlexMari Data 5 iulie 2020 09:07:50
Problema Arbori indexati binar Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.24 kb
#include<bits/stdc++.h>
using namespace std;

ifstream fin("aib.in");
ofstream fout("aib.out");

int n,aib[100001],m,p;

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

int querysum(int poz)
{
    int i,ans=0;
    for(i=poz;i>=1;i-=i&-i)
        ans+=aib[i];
    return ans;
}

int cautapoz(int val)
{
    int pas=p,ok,i=0;
    while(pas>=1)
    {
        if(aib[i+pas]==val)
            ok=1;
        if(aib[i+pas]<val)
        {
            val=val-aib[i+pas];
            i+=pas;
        }
        pas=pas/2;
        while(pas>=1&&i+pas>n)
            pas=pas/2;

    }
    if(ok==1)
        return i+1;
    return -1;
}
int main()
{
    int i,x,op,y;
    fin>>n>>m;
    for(i=1;i<=n;i++)
        {
            fin>>x;
            update(i,x);
        }
    p=1;
    while(p<=n)
        p=p*2;
    p=p/2;
    for(i=1;i<=m;i++)
    {
        fin>>op;
        if(op<2)
        {
            fin>>x>>y;
            if(op==0)
                update(x,y);
            else
                fout<<querysum(y)-querysum(x-1)<<'\n';
        }
        else
        {
            fin>>x;
            fout<<cautapoz(x)<<'\n';
        }
    }
    return 0;
}