poj 3468 整理一下线段树的写法

// 对于延迟更新，我们在updata 和query的时候 pushdown和pushup两个东西都要存在 

#include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>
using namespace std;
typedef long long ll;
struct node
{
    ll l,r,sum,add;
} tree[*];
ll a[];
//ll x,y;
void pushup(int id)
{
    tree[id].sum=tree[id*].sum+tree[id*+].sum;
}
void build(ll l,ll r,int id)
{
    if(l==r)
    {
        tree[id].sum=a[l];
        return;
    }
    tree[id].l=l;
    tree[id].r=r;
    tree[id].add=;
    ll mid=(l+r)/;
    build(l,mid,id*);
    build(mid+,r,id*+);
    pushup(id);
}
void pushdown(int id)
{
    if(tree[id].add)
    {
        tree[id*].add +=tree[id].add;
        tree[id*+].add += tree[id].add;

        tree[id*].sum += (tree[id*].r-tree[id*].l+)*(tree[id*].add);
        tree[id*+].sum += (tree[id*+].r-tree[id*+].l+)*(tree[id*+].add);
        tree[id].add=;
    }
}

void updata(ll x,ll y,ll l,ll r,int id,ll k)
{
    if(x<=l && r<=y)// 在区间里面 就可以做一定操作
    {
        tree[id].sum += (r-l+)*k;
        tree[id].add += k;
        return;
    }
    pushdown(id);//
    ll mid=(l+r)/;
    if(x <= mid) updata(x,y,l,mid,id*,k);
    if(y > mid)  updata(x,y,mid+,r,id*+,k);
    pushup(id);
}

ll query(ll x,ll y,ll l,ll r,int id)
{
    if(x<=l && r<=y)
    {
        return tree[id].sum;
    }
    pushdown(id);
    ll mid=(l+r)/;
    ll sum=;
    if(x<=mid) sum+=query(x,y,l,mid,id*);
    if(y>mid)  sum+=query(x,y,mid+,r,id*+);
    pushup(id);//
    return sum;
}
int main()
{
    int n,q;
    ll x,y,k;
    while(scanf("%d %d",&n,&q)!=EOF)
    {
        for(int i=; i<=n; i++)
        {
            scanf("%d",&a[i]);
        }
        build(,n,);
        while(q--)
        {
            char s[];
            scanf("%s",s);
            if(s[]=='Q')
            {
                scanf("%lld %lld",&x,&y);
                printf("%lld\n",query(x,y,,n,));
            }
            else if(s[]=='C')
            {
                scanf("%lld %lld %lld",&x,&y,&k);
                updata(x,y,,n,,k);
            }
        }
    }

    return ;
}