poj 2155 Matrix(二维树状数组)

　　二维树状数组【区间更新，单点查询】，一道简单题！

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 1 #include <cstdio>
 2 #include <cstring>
 3 #include <algorithm>
 4 
 5 using namespace std;
 6 
 7 const int maxn = 1005;
 8 struct BIT2D {
 9     int size;
10     bool val[maxn][maxn];
11 
12     void init() {
13         memset(val, false, sizeof(val));
14     }
15 
16     void addArea(int x, int y) {
17         for (; x > 0; x -= (-x) & x) {
18             for (int j = y; j > 0; j -= (-j) & j) {
19                 val[x][j] = !val[x][j];
20             }
21         }
22     }
23 
24     bool getPoint(int x, int y) {
25         bool ans = false;
26 
27         for (; x <= size; x += (-x) & x) {
28             for (int j = y; j <= size; j += (-j) & j) {
29                 ans ^= val[x][j];
30             }
31         }
32 
33         return ans;
34     }
35 
36     void print() {
37         for (int i = 1; i <= size; i++) {
38             for (int j = 1; j <= size; j++) {
39                 printf("%d ", val[i][j]);
40             }
41             puts("");
42         }
43         puts("~~~");
44     }
45 } bit;
46 
47 void deal(int op) {
48     char buf[3];
49     int x1, x2, y1, y2;
50 
51     bit.init();
52     while (op--) {
53         scanf("%s", buf);
54         if (buf[0] == 'Q') {
55             scanf("%d%d", &x1, &y1);
56 //            printf("hell?? %d %d\n", x1, y1);
57             printf("%d\n", bit.getPoint(x1, y1));
58         } else {
59             scanf("%d%d%d%d", &x1, &y1, &x2, &y2);
60             bit.addArea(x1 - 1, y1 - 1);
61             bit.addArea(x1 - 1, y2);
62             bit.addArea(x2, y1 - 1);
63             bit.addArea(x2, y2);
64         }
65 //        bit.print();
66     }
67     puts("");
68 }
69 
70 int main() {
71     int T;
72 
73 //    freopen("in", "r", stdin);
74     scanf("%d", &T);
75     while (T--) {
76         int op;
77 
78         scanf("%d%d", &bit.size, &op);
79         deal(op);
80     }
81 
82     return 0;
83 }

——written by Lyon

posted @ 2012-10-31 22:18 LyonLys 阅读(158) 评论(0) 收藏举报

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