0131

今天学习的是：树状数组

https://www.luogu.com.cn/problem/P3374

 1 #include<iostream>
 2 using namespace std;
 3 int n,m,c[500001],a[5000001];
 4 int lowbit(int i)
 5 {
 6     return i&(-i);
 7 }
 8 void cc(int i,int data)
 9 {
10     while(i<=n) c[i]+=data,i+=lowbit(i);
11 }
12 int sum1(int k)
13 {
14     int s=0;
15     while(k>0) s+=c[k],k-=lowbit(k);
16     return s;
17 }
18 int main()
19 {
20      int x1,x2;
21     cin>>n>>m;
22     for(int i=1;i<=n;i++)
23     {
24         cin>>a[i];
25         cc(i,a[i]);
26     }
27     while(m--)
28     {
29         int o;
30         cin>>o>>x1>>x2;
31         if(o==1) cc(x1,x2);
32         else cout<<sum1(x2)-sum1(x1-1)<<endl;
33     }
34     return 0;
35 }
View Code

https://www.luogu.com.cn/problem/P3368

 1 #include<iostream>
 2 using namespace std;
 3 int n,m,a[500001];
 4 long long c[500001];
 5 int lowbit(int x)
 6 {
 7     return x&(-x);
 8 }
 9 void cc(int x,int k)
10 {
11     while(x<=n)
12     {
13         c[x]+=k;
14         x+=lowbit(x);
15     }
16     return;
17 }
18 long long sum(int x)
19 {
20     long long res=0;
21     while(x)
22     {
23         res+=c[x];
24         x-=lowbit(x);
25     }
26     return res;
27 }
28 int main()
29 {
30     cin>>n>>m;
31     for(int i=1;i<=n;i++)
32     {
33         cin>>a[i];
34         cc(i,a[i]-a[i-1]);
35     }
36     while(m--)
37     {
38         int op;cin>>op;
39         if(op==1)
40         {
41             int l,r,k;
42             cin>>l>>r>>k;
43             cc(l,k),cc(r+1,-k);
44         }
45         else
46         {
47             int x;
48             cin>>x;
49             cout<<sum(x)<<endl;
50         }
51     }
52     return 0;
53 }
View Code

 

posted @ 2026-01-31 21:03  Guo5919  阅读(0)  评论(0)    收藏  举报