Mai intai trebuie sa te autentifici.
Cod sursa(job #2304253)
| Utilizator | Data | 17 decembrie 2018 20:13:50 | |
|---|---|---|---|
| Problema | Arbori indexati binar | Scor | 100 |
| Compilator | cpp-64 | Status | done |
| Runda | Arhiva educationala | Marime | 1.16 kb |
#include <bits/stdc++.h>
using namespace std;
int n,m;
int AIB[100005];
int lsb(int x){
return x&(-x);
}
void Update(int poz,int val){
for(int i=poz;i<=n;i+=lsb(i))
AIB[i]+=val;
}
int Query(int poz){
int ans=0;
for(int i=poz;i>0;i-=lsb(i))
ans+=AIB[i];
return ans;
}
int Solve(int Sum){
int st=1,dr=n;
while(st<=dr){
int mij=(st+dr)>>1;
int S=Query(mij);
if(S<Sum)
st=mij+1;
else if(S>Sum)
dr=mij-1;
else return mij;
}
return -1;
}
int main(){
freopen("aib.in","r",stdin);
freopen("aib.out","w",stdout);
scanf("%d %d",&n,&m);
for(int i=1;i<=n;++i){
int x;
scanf("%d",&x);
Update(i,x);
}
for(int i=1;i<=m;++i){
int t,a,b;
scanf("%d",&t);
if(t==0){
scanf("%d %d",&a,&b);
Update(a,b);
}
else if(t==1){
scanf("%d %d",&a,&b);
printf("%d\n",Query(b)-Query(a-1));
}
else{
scanf("%d",&a);
printf("%d\n",Solve(a));
}
}
return 0;
}
