Cod sursa(job #3160688)

Utilizator Horia123144Musat Horia Gabriel Horia123144 Data 24 octombrie 2023 20:58:20
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.08 kb
#include <bits/stdc++.h>

using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int n,m,A[100005];
void update(int p, int x)
{
    for(int i=p; i<=n; i+=(i&-i))
        A[i]+=x;
}
int query(int p)
{
    long long s=0;
    for(int i=p; i>=1; i-=(i&-i))
        s+=A[i];
    return s;
}
int op2(int s)
{
    int st=1,dr=n;
    while(st<=dr)
    {
        int mid=(st+dr)/2;
        int smid=query(mid);
        if(smid==s)
            return mid;
        else if(smid<s)
            st=mid+1;
        else
            dr=mid-1;
    }
    return -1;
}
int main()
{
    int op,a,b;
    fin>>n>>m;
    for(int i=1; i<=n; i++)
    {
        fin>>a;
        update(i,a);
    }
    for(int z=1; z<=m; z++)
    {
        fin>>op;
        if(op==0)
        {
            fin>>a>>b;
            update(a,b);
        }
        else if(op==1)
        {
            fin>>a>>b;
            fout<<query(b)-query(a-1)<<'\n';
        }
        else
        {
            fin>>a;
            fout<<op2(a)<<'\n';
        }
    }
    return 0;
}