Cod sursa(job #2302983)
Utilizator | Data | 15 decembrie 2018 12:52:22 | |
---|---|---|---|
Problema | Arbori indexati binar | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 1.84 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream f("aib.in");
ofstream g("aib.out");
class BIT
{
private:
int *a,N;
void desc(int &x)
{
x-=(x&(-x));
}
void asc(int &x)
{
x+=(x&(-x));
}
public:
BIT(int n)
{
a=new int[n+5]();
N=n;
}
void update(int poz, int val)
{
while(poz<=N)
{
a[poz]+=val;
asc(poz);
}
}
int query(int poz)
{
int sum=0;
while(poz>0)
{
sum+=a[poz];
desc(poz);
}
return sum;
}
int S_bin(int val)
{
int lo=1,hi=N,mid,s;
while(lo<=hi)
{
mid=(lo+hi)>>1;
s=query(mid);
if(s==val) return mid;
if(s<val) lo=mid+1;
else hi=mid-1;
}
return -1;
}
};
int main()
{
int n,i,x,y,op,m;
f>>n>>m;
BIT v(n);
for(i=1;i<=n;i++)
{
f>>x;
v.update(i,x);
}
while(m--)
{
f>>op;
switch (op)
{
case 0:
{
f>>x>>y;
v.update(x,y);
break;
}
case 1:
{
f>>x>>y;
g<<v.query(y)-v.query(x-1)<<'\n';
break;
}
case 2:
{
f>>x;
g<<v.S_bin(x)<<'\n';
break;
}
}
}
return 0;
}