树状数组模板

Posted 2022-10-03 msmw

树状数组模板

 

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 const int maxn=5e5+5;
 5 
 6 int n,m;
 7 int a[maxn];
 8 ll tree[maxn];
 9 
10 int lowbit(int x)
11     return x&(-x);
12 
13 
14 void add(int idx,int v)
15     for(int i=idx;i<=n;i+=lowbit(i))
16         tree[i]+=v;
17  
18 
19 ll sum(int x)
20     ll ans=0;
21     while(x!=0)
22         ans+=tree[x];
23         x-=lowbit(x);
24     
25     return ans;
26     
27 
28 int main()
29     cin>>n>>m;
30     for(int i=1;i<=n;i++) cin>>a[i],add(i,a[i]);
31     for(int i=1;i<=m;i++)
32         int op,x,y;cin>>op>>x>>y;
33         if(op==1) add(x,y);
34             else cout <<sum(y)-sum(x-1)<<"\n";
35     
36     
37     return 0;
38