codevs 1082 线段树练习3 （线段树）

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <string>
#include <cstring>
#include <algorithm>

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int inf=0x3f3f3f3f;
const int maxn=2e5+10;
int n,m,x,y,v,op;
ll ans;
ll a[maxn];

struct node{
    int l,r,lazy;
    ll w;
}tree[maxn<<2];

void build(int l,int r,int rt){
    tree[rt].l=l;
    tree[rt].r=r;
    if(l==r){
        tree[rt].w=a[l];
        return;
    }
    int mid=(l+r)/2;
    build(l,mid,rt*2);
    build(mid+1,r,rt*2+1);
    tree[rt].w=tree[rt*2].w+tree[rt*2+1].w;
}

void pushdown(int rt){
    tree[rt*2].lazy+=tree[rt].lazy;
    tree[rt*2+1].lazy+=tree[rt].lazy;
    tree[rt*2].w+=1ll*tree[rt].lazy*(tree[rt*2].r-tree[rt*2].l+1);
    tree[rt*2+1].w+=1ll*tree[rt].lazy*(tree[rt*2+1].r-tree[rt*2+1].l+1);
    tree[rt].lazy=0;
}

void update(int rt){
    if(tree[rt].l>=x && tree[rt].r<=y){
        tree[rt].w+=1ll*v*(tree[rt].r-tree[rt].l+1);
        tree[rt].lazy+=v;
        return;
    }
    if(tree[rt].lazy) pushdown(rt);
    int mid=(tree[rt].l+tree[rt].r)/2;
    if(x<=mid) update(rt*2);
    if(y>mid) update(rt*2+1);
    tree[rt].w=tree[rt*2].w+tree[rt*2+1].w;
}

void query(int rt){
    if(tree[rt].l>=x && tree[rt].r<=y){
        ans+=tree[rt].w;
        return;
    }
    if(tree[rt].lazy) pushdown(rt);
    int mid=(tree[rt].l+tree[rt].r)/2;
    if(x<=mid) query(rt*2);
    if(y>mid) query(rt*2+1);
}

int main(){
    scanf("%d",&n);
    for(int i=1;i<=n;i++){
        scanf("%lld",&a[i]);
    }
    build(1,n,1);
    scanf("%d",&m);
    for(int i=1;i<=m;i++){
        scanf("%d",&op);
        if(op==1){
            scanf("%d%d%d",&x,&y,&v);
            update(1);
        }
        if(op==2){
            ans=0;
            scanf("%d%d",&x,&y);
            query(1);
            printf("%lld\n",ans);
        }
    }
    return 0;
}