HDU 1556 Color the ball【树状数组】

题意：给出n个区间，每次给这个区间里面的数加1，询问单点的值

一维的区间更新，单点查询，还是那篇论文里面讲了的

 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=100005;

17 

18 int n;

19 int c[maxn];

20 

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

22 

23 int sum(int x){

24     int ret=0;

25     while(x>0){

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

27     }

28     return ret;

29 }

30 

31 void add(int x,int d){

32     while(x<=n){

33         c[x]+=d; x+=lowbit(x);

34     }

35 }

36 

37 int main(){

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

39         if(n == 0) break;

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

41         for(int i=1;i<=n;i++){

42             int a,b;

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

44             add(a,1);add(b+1,-1);

45         }

46         printf("%d",sum(1));

47         for(int i=2;i <= n;i++)

48         printf(" %d",sum(i));

49         printf("\n");

50     }

51     return 0;

52 }

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