树状数组模板2（区间修改，单点查询）

```cpp

#include <iostream>
#include <cstdio>
#define lowbit(x) x & -x
using namespace std;
long long tree[500005];
int n, m;
void add(int x, long long num)
{
while (x <= n)
{
tree[x] += num;
x += lowbit(x);
}
}
long long query(int x)
{
long long ans = 0;
while (x)
{
ans += tree[x];
x -= lowbit(x);
}
return ans;
}
int main()
{
scanf("%d%d", &n, &m);
long long last = 0, now;
for (int i = 1; i <= n; i++)
{
scanf("%lld", &now);
add(i, now - last);
last = now;
}
int flg;
while (m--)
{
scanf("%d", &flg);
if (flg == 1)
{
int x, y;
long long k;
scanf("%d%d%lld", &x, &y, &k);
add(x, k);
add(y + 1, -k);
}
else
if (flg == 2)
{
int x;
scanf("%d", &x);
printf("%lld\n", query(x));
}
}
return 0;
}

```