hdu 1166 敌兵布阵 （树状数组）

 1 #include<stdio.h>

 2 #include<string.h>

 3 #define N 600000

 4 int n;

 5 int a[N],c[N];

 6 int lowbit(int x)

 7 {

 8     return x&(-x);

 9 }

10 int sum(int k)

11 {

12     int ans=0;

13     while(k>0)

14     {

15         ans+=c[k];

16         k=k-lowbit(k);

17     }

18     return ans;

19 }

20 int add(int pos ,int num)

21 {

22     while(pos<=n)

23     {

24         c[pos]+=num;

25         pos+=lowbit(pos);

26     }

27 }

28 int main()

29 {

30     int T,l,i;

31     scanf("%d",&T);

32     char str[10];

33     for(l=1;l<=T;l++)

34     {

35         scanf("%d",&n);

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

37         a[0]=0;

38         for(i=1;i<=n;i++)

39         {

40             scanf("%d",&a[i]);

41             add(i,a[i]);

42 

43         }

44         printf("Case %d:\n",l);

45         while(scanf("%s",str)!=EOF)

46         {

47             if(strcmp(str,"End")==0)break;

48             if(strcmp(str,"Query")==0)

49             {

50                 int x,y;

51                 scanf("%d%d",&x,&y);

52                 int t;

53                 if(x>y)

54                 {

55                     t=x;x=y;y=t;

56                 }

57                 printf("%d\n",sum(y)-sum(x-1));

58             }

59             else

60             {

61                 int pos,y;

62                 if(strcmp(str,"Add")==0)

63                 {

64                     scanf("%d%d",&pos,&y);

65                     add(pos,y);

66 

67                 }

68                 else

69                 {

70                      scanf("%d%d",&pos,&y);

71                       add(pos,-y);

72 

73                 }

74 

75             }

76         }

77 

78     }

79 }