Cod sursa(job #2393173)

Utilizator dinugaftonGafton Dinu dinugafton Data 30 martie 2019 22:53:50
Problema Arbori indexati binar Scor 40
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.02 kb
#include<bits/stdc++.h>
using namespace std;
#define ion 100005
int n,m,a[ion],bit[ion],k,x,y,c;
int suma(int index){
	int sum=0;
	while(index>0){
		sum+=bit[index];
		index-=index&(-index);
	}
	return sum;
}
void update(int index, int val){
	while(index<=n){
		bit[index]+=val;
		index+=index&(-index);
	}
}
void creare(){
	for(int i=1;i<=n;i++)
	    update(i,a[i]);
}
int cautare(){
	int st=1,dr=n;
    while(st<=dr){
        int mid=(st+dr)/2;
        int aux=suma(mid);
        if(aux>k)dr=mid-1;
        else if(aux<k)st=mid+1;
        else return mid;
    }
    return -1;

}
int main(){
	ifstream cin("aib.in");
	ofstream cout("aib.out");
	cin>>n>>m;
	for(int i=1;i<=n;i++)
	    cin>>a[i];
	creare();
	for(int i=1;i<=m;i++){
		cin>>c;
		if(c==1||c==0){
			cin>>x>>y;
		}else cin>>k;
		switch(c){
			case 0:{
				update(x,y);
				break;
			}
			case 1:{
				cout<<suma(y)-suma(x-1)<<'\n';
				break;
			}
			case 2:{
				cout<<cautare()<<endl;
				break;
			}
		}
	}
	return 0;
}