POJ 1195 Mobile phones【 二维树状数组 】

题意：基础的二维数组，注意 0 + lowbit(0)会陷入无限循环-----

之前做一道一维的一直tle,就是因为这个--------------------------

 1 #include<iostream>  

 2 #include<cstdio>  

 3 #include<cstring> 

 4 #include <cmath> 

 5 #include<stack>

 6 #include<vector>

 7 #include<map> 

 8 #include<set>

 9 #include<queue> 

10 #include<algorithm>  

11 using namespace std;

12 

13 typedef long long LL;

14 const int INF = (1<<30)-1;

15 const int mod=1000000007;

16 const int maxn=1000005;

17 

18 int c[1055][1055];

19 int n;

20 

21 int lowbit(int x){ return x & (-x);}

22 

23 int sum(int x,int y){

24     int ret = 0,y1;

25     while(x > 0){

26         y1 = y;

27         while( y1 > 0){

28             ret += c[x][y1];y1 -= lowbit(y1);

29         }

30         x-=lowbit(x);

31     }

32     return ret;

33 }

34 

35 void add(int x,int y,int d){

36     int y1;

37     while(x <= n){

38         y1 = y;

39         while(y1 <= n){

40             c[x][y1] += d; y1 += lowbit(y1);

41         }

42         x += lowbit(x);

43     }

44 }

45 

46 int main(){

47     int cmd;

48     while(scanf("%d %d",&cmd,&n) != EOF){

49         memset(c,0,sizeof(c));

50         while(scanf("%d",&cmd) != EOF && cmd != 3){

51             if(cmd == 1){

52                 int x,y,d;

53                 scanf("%d %d %d",&x,&y,&d);x++;y++;

54                 add(x,y,d);

55             }

56             else{

57                 int x,y,xx,yy;

58                 int ret = 0;

59                 scanf("%d %d %d %d",&x,&y,&xx,&yy);

60                 x++;y++;xx++;yy++;

61                 ret = sum(xx,yy) - sum(x-1,yy) - sum(xx,y-1) + sum(x-1,y-1);

62                 printf("%d\n",ret);

63             }

64         }

65     }

66     return 0;

67 }

View Code

 

 

 

 

 

 

 

 

 

话说好几天没有写代码了的说啊----

加油↖(^ω^)↗

goooooooooooooooooo----