POJ 1195 Mobile phones

题目链接：http://poj.org/problem?id=1195

二维树状数组的应用

 1 #include <cstdio>
 2 #include <cstring>
 3 #include <cstdlib>
 4 
 5 const int MAXN = 1200;
 6 int S;
 7 int C[MAXN][MAXN];
 8 
 9 int lowbit( int x )
10 {
11     return x & -x;
12 }
13 
14 void Add( int x, int y, int add )
15 {
16     int tpy;
17     while ( x <= S )
18     {
19         tpy = y;
20         while ( tpy <= S )
21         {
22             C[x][tpy] += add;
23             tpy += lowbit(tpy);
24         }
25         x += lowbit(x);
26     }
27     return;
28 }
29 
30 int Sum( int x, int y )
31 {
32     int ret = 0;
33     while ( x > 0 )
34     {
35         int tpy = y;
36         while ( tpy > 0 )
37         {
38             ret += C[x][tpy];
39             tpy -= lowbit(tpy);
40         }
41         x -= lowbit(x);
42     }
43     return ret;
44 }
45 
46 int main()
47 {
48     int op, add;
49     int x1, y1, x2, y2;
50     while( ~scanf( "%d%d", &op, &S ) )
51     {
52         memset( C, 0, sizeof(C) );
53         while ( scanf( "%d", &op ), op != 3 )
54         {
55             if ( op == 1 )
56             {
57                 scanf( "%d%d%d", &x1, &y1, &add );
58                 ++x1, ++y1;
59                 Add( x1, y1, add );
60             }
61             else
62             {
63                 scanf( "%d%d%d%d", &x1, &y1, &x2, &y2 );
64                 ++x1, ++y1;
65                 ++x2, ++y2;
66                 printf("%d\n", Sum(x2, y2) - Sum(x1 - 1, y2) - Sum(x2, y1 - 1) + Sum(x1 - 1, y1 - 1) );
67             }
68         }
69     }
70     return 0;
71 }

 

posted @ 2013-04-15 21:05  冰鸮  阅读(204)  评论(0)    收藏  举报