hdu 1166 线段树（单点增减 区间求和）

Sample Input
1
10
1 2 3 4 5 6 7 8 9 10
Query 1 3
Add 3 6
Query 2 7
Sub 10 2
Add 6 3
Query 3 10
End

Sample Output
Case 1:
6
33
59

 # include <iostream>
 # include <cstdio>
 # include <cstring>
 # include <algorithm>
 # include <cmath>
 # include <queue>
 # define LL long long
 using namespace std ;

 const int maxn = ;

 int sum[maxn<<] ; //结点开4倍

 void PushUP(int rt) //更新到父节点
 {
     sum[rt] = sum[rt * ] + sum[rt *  + ] ; //rt 为当前结点
 }

 void build(int l , int r , int rt) //构建线段树
 {
     if (l == r)
     {
         scanf("%d" , &sum[rt]) ;
         return ;
     }
     int m = (l + r) /  ;
     build(l , m , rt * ) ;
     build(m +  , r , rt *  +) ;
     PushUP(rt) ;
 }

 void updata(int p , int add , int l , int r , int rt)  //单点增减
 {
     if (l == r)
     {
         sum[rt] += add ;
         return ;
     }
     int m = (l + r) /  ;
     if (p <= m)
        updata(p , add , l , m , rt * ) ;
     else
        updata(p , add , m +  , r , rt *  + ) ;
     PushUP(rt) ;
 }

 int query(int L , int R , int l , int r , int rt)  //区间求和
 {
     if (L <= l && r <= R)
         return sum[rt] ;
     int m = (l + r) /  ;
     int ret =  ;
     if (L <= m)
        ret += query(L , R , l , m , rt * ) ;
     if (R > m)
        ret += query(L , R , m +  , r , rt *  + ) ;
     return ret ;
 }

 int main ()
 {
     //freopen("in.txt","r",stdin) ;
     int T  , n;
     int Case =  ;
     scanf("%d" , &T) ;
     while (T--)
     {
         scanf("%d" , &n) ;
         build( , n , ) ;
         char op[] ;
         Case++ ;
         printf("Case %d:\n" , Case) ;
         while (scanf("%s" , op))
         {
             if (op[] == 'E') //结束
                break ;
             int a , b ;
             scanf("%d %d" , &a , &b) ;
             if (op[] == 'Q') //求a,b区间的和
                printf("%d\n", query(a , b ,  , n , )) ;
             else if (op[] == 'S')  //将第a个地方减少b
                updata(a , -b ,  , n , ) ;
             else if (op[] == 'A')   //将第a个地方增加b
                updata(a , b ,  , n , ) ;
         }
     }

     return  ;
 }