Cod sursa(job #3151396)

Utilizator ukeremKerem U ukerem Data 20 septembrie 2023 22:57:40
Problema Datorii Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.01 kb
#include <fstream>
#include <vector>
using namespace std;
ifstream in("datorii.in");
ofstream out("datorii.out");
int N;
vector <int> bit(15005, 0);
void update(int i,int val)
{
    while(i<=N)
    {
        bit[i]+=val;
        i+= i & -i;
    }
}
int prefixSum(int i)
{
    int sum=0;
    while(i>0)
    {
        sum+=bit[i];
        i-= i & -i;
    }
    return sum;
}
int rangeSum(int i, int j)
{
    return prefixSum(j) - prefixSum(i-1);
}
int lbound(int ca)
{
    int l=1,r=N,mid=-1,aux;
    while(l<r)
    {
        mid=(l+r)/2;
        aux=prefixSum(mid);
        if(aux>=ca)
            r=mid;
        else
            l=mid+1;
    }
    return l;
}
int main()
{
    int x,m;
    in>>N>>m;
    for(int i=1;i<=N;i++)
    {
        in>>x;
        update(i,x);
    }
    int op,a,b;
    for(int i=1;i<=m;i++)
    {
        in>>op>>a>>b;
        if(op==0)
            update(a,-1*b);
        else if(op==1)
            out<<rangeSum(a,b)<<'\n';
    }
    return 0;
}