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("
");
50     }
51     return 0;
52 }

View Code