树状数组模板

int c[MAX];
int lowbit(int x)
{
	return x & (-x);
}
int sum(int x)
{
	int s = 0;
	while(x > 0)
	{
		s += c[x];
		x -= lowbit(x);
	}
	return s;
}
int update(int x, int value)
{
	while(x <= MAX)
	{
		c[x] += value;
		x += lowbit(x);
	}
}