POJ 1195 Mobile phones

 1 #include <cstdio>
 2 #include <cstring>
 3 #define lowbit(x) (x)&(-x)
 4 
 5 int S;
 6 int c[1030][1030];
 7 
 8 void add(int x, int y, int val)
 9 {
10     for(int i = x; i <= S; i += lowbit(i))
11         for(int j = y; j <= S; j +=lowbit(j))
12             c[i][j] += val;
13 }
14 
15 int sum(int x, int y)
16 {
17     int ret = 0;
18     for(int i = x; i > 0; i -= lowbit(i))
19         for(int j = y; j > 0; j -= lowbit(j))
20             ret += c[i][j];
21     return ret;
22 }
23 
24 int getans(int x1, int y1, int x2, int y2)
25 {
26     return sum(x2, y2)-sum(x1-1, y2)-sum(x2, y1-1)+sum(x1-1, y1-1);
27 }
28 
29 int main()
30 {
31     int op;
32     while(scanf("%d", &op), op != 3){
33         if(op == 0){
34             scanf("%d", &S);
35             memset(c, 0, sizeof(c));
36         }
37         else if(op == 1){
38             int x, y, a;
39             scanf("%d%d%d", &x, &y, &a);
40             add(x+1, y+1, a);   //坐标全部加1
41         }
42         else if(op == 2){
43             int l, b, r, t;
44             scanf("%d%d%d%d", &l, &b, &r, &t);
45             printf("%d\n", getans(l+1, b+1, r+1, t+1)); //坐标全部加1
46         }
47     }
48     return 0;
49 }