P3368 【模板】树状数组 2

#include<bits/stdc++.h>
using namespace std;
#define x first
#define y second
typedef pair<int,int> PII;
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int uint;
typedef vector<string> VS;
typedef vector<int> VI;
typedef vector<vector<int>> VVI;
const int N = 500010;
ll c[N];
int n,m;
inline int lowbit(int x) {return x&-x;}
inline void update(int x,int d) {while(x<=n){c[x] += d, x += lowbit(x);}}
inline ll sum(int x) {ll res = 0;while(x){res += c[x], x -= lowbit(x);}return res;}
void solve()
{
    cin>>n>>m;
	for(int i=1;i<=n;++i)
	{
		int a;
		cin>>a;
		update(i,a);
		update(i+1,-a);
	}
	
	for(int i=0;i<m;++i)
	{
		int op,x,y,d;
		cin>>op;
		if(op&1)
		{
			cin>>x>>y>>d;
			update(x,d);
			update(y+1,-d);
		}
		else
		{
			cin>>x;
			cout<<sum(x)<<'\n';
		}
	}
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int T = 1;
	//cin>>T;
	while(T--)
	{
		solve();
	}
}