二维树状数组模板

Posted 2020-10-02 seventh成长中---

完全版

 1 #include <cstdio>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <algorithm>
 5 using namespace std;
 6 int lowbit(int x)
 7 {
 8     return x&(-x);
 9 }
10 struct tree_arr
11 {
12     int c[1005];
13     tree_arr()
14     {
15         clear();
16     }
17     void clear()
18     {
19         memset(c,0,sizeof(c));
20     }
21     int get_sum(int x)
22     {
23         int sum=0;
24         while(x)
25         {
26             sum+=c[x];
27             x-=lowbit(x);
28         }
29         return sum;
30     }
31     void update(int x,int d,int n)
32     {
33         while(x<=n)
34         {
35             c[x]+=d;
36             x+=lowbit(x);
37         }
38     }
39 } r[1005];
40 int get_sum(int x,int y)///(x,y)
41 {
42     int sum=0;
43     while(x)
44     {
45         sum+=r[x].get_sum(y);
46         x-=lowbit(x);
47     }
48     return sum;
49 }
50 void update(int x,int y,int d,int n,int m)///n行，m列
51 {
52     while(x<=n)
53     {
54         r[x].update(y,d,m);
55         x+=lowbit(x);
56     }
57 
58 }
59 int main()
60 {
61     int i,j,n=10,m=10;
62     memset(r,0,sizeof(r));
63     for(i=1; i<=n; i++)
64     {
65         for(j=1; j<=m; j++)
66         {
67             update(i,j,1,n,m);
68         }
69     }
70     for(i=1; i<=n; i++)
71     {
72         for(j=1; j<=m; j++)
73         {
74             printf("%3d ",get_sum(i,j));
75         }
76         puts("");
77     }
78     return 0;
79 }

简化版

 1 int c[MAX][MAX];
 2 int n,m;
 3 int Lowbit(int x)
 4 {
 5     return x & (-x);
 6 }
 7 void Updata(int x,int y,int d)
 8 {
 9     int i,k;
10     for(i=x; i<=n; i+=Lowbit(i))
11         for(k=y; k<=m; k+=Lowbit(k))
12             c[i][k]+=d;
13 }
14 int Get(int x,int y)
15 {
16     int i,k,sum = 0;
17     for(i=x; i>0; i-=Lowbit(i))
18         for(k=y; k>0; k-=Lowbit(k))
19             sum += c[i][k];
20     return sum;
21 }