Cod sursa(job #3267200)
Utilizator | Data | 11 ianuarie 2025 10:19:57 | |
---|---|---|---|
Problema | Arbori indexati binar | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 1.8 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
using ll = long long;
int aib[100005];
int n,m,op,x,a,b;
void update(int i,int x) {
for (int crt = i;crt<=n;crt+=(crt&-crt)) {
aib[crt]+=x;
}
}
int query(int i) {
int s = 0;
for (int j = i;j>=1;j-=j&(-j)) {
s+=aib[j];
}
return s;
}
void create() {
for (int i = 1;i<=n;++i) {
fin>>x;
update(i,x);
}
}
int main() {
fin>>n>>m;
create();
for (int i = 1;i<=m;++i) {
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 if (op==2) {
fin>>a;
int l = 1,r = n,rez = n+1;
while(l<=r) {
int mid = (l+r)/2;
int sum = query(mid);
if (l==r) {
if (sum==a)
rez = mid;
break;
}
if (sum>=a) {
r = mid;
rez = mid;
} else {
l = mid+1;
}
}
if (rez==n+1)
rez = -1;
fout<<rez<<'\n';
}
}
return 0;
}