hdu1166敌兵布阵（线段树）

线段树 单点更新

http://acm.hdu.edu.cn/showproblem.php?pid=1166

View Code

 1 #include<stdio.h>

 2 #include<string.h>

 3 int sum[1000001];

 4 void push(int w)

 5 {

 6     sum[w] = sum[2*w]+sum[2*w+1];//更新节点值

 7 }

 8 void build(int l,int r,int w)

 9 {

10     if(l==r)

11     {

12         scanf("%d",&sum[w]);

13         return;

14     }

15     int m = (l+r)/2;

16     build(l,m,2*w);

17     build(m+1,r,2*w+1);

18     push(w);

19 }

20 void add(int p,int d,int l,int r,int w)

21 {

22     if(l==r)

23     {

24         sum[w]+=d;

25         return ;

26     }

27     int m = (l+r)/2;

28     if(p<=m)

29         add(p,d,l,m,2*w);

30     else

31         add(p,d,m+1,r,2*w+1);

32     push(w);

33 }

34 int query(int p1,int p2,int l,int r,int w)

35 {

36     if(p1<=l&&p2>=r)//区间被完全覆盖

37         return sum[w];    

38     int m = (l+r)/2;

39     int re = 0;

40     if(p1<=m)

41         re+=query(p1,p2,l,m,2*w);

42     if(p2>m)

43         re+=query(p1,p2,m+1,r,2*w+1);

44     return re;

45 }

46 int main()

47 {

48     int i,j,k,n,t,a,b;

49     char c[11];

50     scanf("%d", &t);

51     for(i = 1; i <= t ; i++)

52     {

53         memset(sum,0,sizeof(sum));

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

55         build(1,n,1);        

56         getchar();

57         printf("Case %d:\n",i);

58         while(scanf("%s",c)!=EOF)

59         {

60             if(strcmp(c,"End")==0)

61             break;

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

63             {

64                 scanf("%d%d", &a,&b);

65                 add(a,b,1,n,1);

66             }

67             if(strcmp(c,"Sub")==0)

68             {

69                 scanf("%d%d", &a,&b);

70                 add(a,-b,1,n,1);

71             }

72             if(strcmp(c,"Query")==0)

73             {

74                 scanf("%d%d", &a,&b);            

75                 printf("%d\n",query(a,b,1,n,1));

76             }

77         }

78     }

79     return 0;

80 }