Description
You have N integers, A1, A2, ... , AN. You need to deal with two kinds of operations. One type of operation is to add some given number to each number in a given interval. The other is to ask for the sum of numbers in a given interval.
题意很好理解，就是标准的线段树区间更新问题，可以说是模板。
不过因为写的不熟练，被坑了两个WA，错的地方在代码里标出来了。。。
代码如下：
#include<iostream>
#include<cstdio> #define lson L,M,po*2
#define rson M+1,R,po*2+1 using namespace std; long long BIT[*];
long long COL[*]; void pushUP(int po)
{
BIT[po]=BIT[po*]+BIT[po*+];
} void pushDown(int po,int len)
{
if(COL[po])
{
BIT[po*]+=(long long)COL[po]*(len-(len/));
BIT[po*+]+=(long long)COL[po]*(len/); COL[po*]+=COL[po]; //注意是+=，不是= ！！！
COL[po*+]+=COL[po];
COL[po]=;
}
} void build_tree(int L,int R,int po)
{
if(L==R)
{
COL[po]=;
cin>>BIT[po];
return;
} int M=(L+R)/; build_tree(lson);
build_tree(rson); pushUP(po);
} long long query(int ql,int qr,int L,int R,int po)
{
if(ql<=L&&qr>=R)
return BIT[po]; pushDown(po,(R-L+)); int M=(L+R)/; if(qr<=M)
return query(ql,qr,lson);
if(ql>M)
return query(ql,qr,rson); return query(ql,qr,rson)+query(ql,qr,lson);
} void update(int ul,int ur,int add,int L,int R,int po)
{
if(ul<=L&&ur>=R)
{
BIT[po]+=(long long)add*(R-L+);
COL[po]+=(long long)add; return;
} pushDown(po,R-L+); int M=(L+R)/; if(ul<=M)
update(ul,ur,add,lson);
if(ur>M)
update(ul,ur,add,rson); pushUP(po);
} int main()
{
int N,Q;
char C;
int a,b,c; while(~scanf("%d %d",&N,&Q))
{
build_tree(,N,); for(int i=;i<Q;++i)
{
cin>>C; if(C=='Q')
{
scanf("%d %d",&a,&b); cout<<query(a,b,,N,)<<endl;
}
else
{
scanf("%d %d %d",&a,&b,&c);
update(a,b,c,,N,);
}
}
} return ;
}