【模板】樹狀數組

#include<stdio.h>
#include<cstdio>
#include<string>
#include<string.h>
#include<vector>
#include<algorithm>
#include<queue>
#include<stack>
#include<math.h>
#include<iomanip>
#include<stdlib.h>
#include<iostream>
#include<list>
#include<fstream>
#include<ostream>
using namespace std;
#define N 500001
int c[N],n;
int lowbit(int x)
{
	return x&(-x);
}
void update(int x,int val)
{
	while(x<=n)
	{
		c[x]+=val;
		x+=lowbit(x);
	}
}
int getsum(int x)
{
	int sum=0;
	while(x>0)
	{
		sum+=c[x];
		x-=lowbit(x);
	}
	return sum;
}