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

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include <cmath>
 #include<stack>
 #include<vector>
 #include<map>
 #include<set>
 #include<queue>
 #include<algorithm>
 using namespace std;

 typedef long long LL;
 const int INF = (<<)-;
 const int mod=;
 const int maxn=;

 int n;
 int c[maxn];

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

 int sum(int x){
     int ret=;
     while(x>){
         ret+=c[x];x-=lowbit(x);
     }
     return ret;
 }

 void add(int x,int d){
     while(x<=n){
         c[x]+=d; x+=lowbit(x);
     }
 }

 int main(){
     while(scanf("%d",&n) != EOF){
         if(n == ) break;
         memset(c,,sizeof(c));
         for(int i=;i<=n;i++){
             int a,b;
             scanf("%d %d",&a,&b);
             add(a,);add(b+,-);
         }
         printf("%d",sum());
         for(int i=;i <= n;i++)
         printf(" %d",sum(i));
         printf("\n");
     }
     return ;
 }