poj 1195 Mobile phones（二维树状数组）

二维树状数组用于求子矩阵的和。

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 1 /*
 2 Author:Zhaofa Fang
 3 Lang:C++
 4 */
 5 #include <cstdio>
 6 #include <cstdlib>
 7 #include <iostream>
 8 #include <cmath>
 9 #include <cstring>
10 #include <algorithm>
11 #include <string>
12 #include <utility>
13 #include <vector>
14 #include <queue>
15 #include <stack>
16 #include <map>
17 #include <set>
18 using namespace std;
19 typedef long long ll;
20 #define pii pair<int,int>
21 #define pb push_back
22 #define mp make_pair
23 #define fi first
24 #define se second
25 #define lowbit(x) (x&(-x))
26 #define INF (1<<30)
27 
28 const int maxn = 1025;
29 int c[maxn][maxn];
30 int n;
31 void add(int x,int y,int v)
32 {
33     for(int i=x;i<=n;i+=lowbit(i))
34         for(int j=y;j<=n;j+=lowbit(j))
35             c[i][j] += v;
36 }
37 int sum(int x,int y)
38 {
39     int res = 0;
40     for(int i=x;i>0;i-=lowbit(i))
41         for(int j=y;j>0;j-=lowbit(j))
42             res += c[i][j];
43     return res;
44 }
45 int main()
46 {
47     #ifndef ONLINE_JUDGE
48     freopen("in","r",stdin);
49     #endif
50     int op;
51     while(~scanf("%d",&op))
52     {
53         if(op == 0)
54         {
55             scanf("%d",&n);
56             memset(c,0,sizeof(c));
57         }
58         else if(op == 1)
59         {
60             int x,y,a;
61             scanf("%d%d%d",&x,&y,&a);
62             add(x+1,y+1,a);
63         }
64         else if(op == 2)
65         {
66             int l,b,r,t;
67             scanf("%d%d%d%d",&l,&b,&r,&t);
68             printf("%d\n",sum(r+1,t+1)+sum(l,b)-sum(l,t+1)-sum(r+1,b));
69         }
70         else break;
71     }
72     return 0;
73 }
posted @ 2012-10-13 22:48  發_  阅读(112)  评论(0)  编辑  收藏  举报