树状数组基本模板

树状数组基本模板

 

lowbit

1 inline int lowbit(int x)
2 {
3     return x & (-x);
4 }

单点修改

1 inline void update(int i, int x)
2 {
3     for (int pos = i; pos < MAXN; pos += lowbit(pos))
4         c[pos] += x;
5 }

单点查询

inline ll query(int x)
{
    int ans = 0;
    for (int pos = x; pos; pos -= lowbit(pos))
        ans += c[pos];
    return ans;
}

区间查询

1 inline ll query(int l, int r)
2 {
3     return query(r) - query(l - 1);
4 }

 

Luogu P3374

【模板】树状数组 1

代码

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 using ll = long long;
 4 #define N 500010
 5 ll c[N];
 6 ll a[N];
 7 inline int lowbit(int x) { return x & (-x); }
 8 inline void update(int i,int x)
 9 {
10     for (int pos = i; pos<N;pos+=lowbit(pos))
11         c[pos] += x;
12 }
13 inline ll query(int x)
14 {
15     int ans = 0;
16     for (int pos = x; pos;pos-=lowbit(pos))
17         ans += c[pos];
18     return ans;
19 }
20 inline ll query(int l,int r)
21 {
22     return query(r) - query(l - 1);
23 }
24 int main()
25 {
26     ios::sync_with_stdio(false);
27     cin.tie(0);
28     int n, m;
29     cin >> n >> m;
30     for (int i = 1; i <= n;i++)
31     {
32         cin >> a[i];
33         update(i, a[i]);
34     }
35     for (int i = 1; i <= m;i++)
36     {
37         ll op, x, y;
38         cin >> op >> x >> y;
39         if(op==1)
40             update(x, y);
41         else
42         {
43             cout << query(x, y)<<"\n";
44         }
45     }
46         return 0;
47 }

 

posted @ 2021-03-24 14:04  icey_z  阅读(282)  评论(0)    收藏  举报