Cod sursa(job #528828)

Utilizator feelshiftFeelshift feelshift Data 3 februarie 2011 15:35:20
Problema Datorii Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.12 kb
// http://infoarena.ro/problema/datorii
// rezolvata cu arbori indexati binar (http://infoarena.ro/aib)
#include <fstream>
using namespace std;

#define maxDays 15002
#define zeros(x) ( (x ^ (x - 1)) & x )

ifstream in("datorii.in");
ofstream out("datorii.out");

int days;
int AIB[maxDays];

void add(int where,int quantity);
int compute(int left,int right);	// returneaza suma elementelor subsecventei (0,where);

int main() {
	int operations,value;
	int first,second;
	bool interogation;

	in >> days >> operations;

	for(int currentDay=1;currentDay<=days;currentDay++) {
		in >> value;
		add(currentDay,value);
	}

	for(int i=1;i<=operations;i++) {
		in >> interogation >> first >> second;

		if(interogation)
			//out << compute(second) - compute(first-1) << "\n";
			out << compute(first,second) << "\n";
		else
			add(first,-second);
	}

	return (0);
}

void add(int where,int quantity) {
	for(int k=where;k<=days;k=k+zeros(k))
		AIB[k] += quantity;
}

int compute(int left,int right) {
	int value = 0;

	for(int k=right;k>=left;k=k-zeros(k))
		value = value + AIB[k];

	return value;
}