poj 3468 线段树 成段增减 区间求和

题意：Q是询问区间和，C是在区间内每个节点加上一个值

Sample Input

10 5
1 2 3 4 5 6 7 8 9 10
Q 4 4
Q 1 10
Q 2 4
C 3 6 3
Q 2 4
Sample Output

4
55
9
15

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

 const int maxn = ;

 LL sum[maxn<<] ; //结点开4倍
 LL add[maxn<<] ; //延迟标记

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

 void PushDown(int rt , int m )  //向下更新
 {
     if (add[rt])
     {
         add[rt * ] += add[rt] ;
         add[rt *  + ] += add[rt] ;
         sum[rt * ] += (m - m / ) * add[rt] ;
         sum[rt *  + ] += (m / ) * add[rt] ;
         add[rt] =  ;
     }
 }

 void build(int l , int r , int rt) //构建线段树
 {
     add[rt] =  ;
     if (l == r)
     {
         cin>>sum[rt];
         return ;
     }
     int m = (l + r) /  ;
     build(l , m , rt * ) ;
     build(m +  , r , rt *  +) ;
     PushUP(rt) ;
 }

 void updata(int L , int R , int c , int l , int r , int rt)  //成段增减
 {
     if (L <= l && r <= R)
         {
             add[rt] += c ;
             sum[rt] += (r - l + ) * c ;
             return  ;
         }
     PushDown(rt , r - l + ) ;
     int m = (l + r) /  ;

     if (L <= m)
        updata(L , R , c , l , m , rt * ) ;
     if (R > m)
        updata(L , R , c , m +  , r , rt *  + ) ;
     PushUP(rt) ;
 }

 LL query(int L , int R , int l , int r , int rt)  //区间求和
 {
     if (L <= l && r <= R)
         return sum[rt] ;
     PushDown(rt , r - l + ) ;
     int m = (l + r) /  ;
     LL 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 n , m ;
     scanf("%d %d" , &n , &m) ;

         build( , n , ) ;
         while(m--)
         {
             char op[] ;
             int a , b , c ;
             scanf("%s" , op) ;
             if(op[] == 'Q')
             {
                 scanf("%d %d" , &a , &b) ;
                 cout<<query(a , b ,  , n , )<<endl ;
             }
             else
             {
               scanf("%d %d %d" , &a , &b , &c) ;
               updata(a , b , c ,  , n , ) ;
             }
         }

     return  ;
 }