代码比较长，还没有完全理解
package info.frady.luogu;import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
public class P3372 {static long[] sum_tree;static long[] tag;static long[] a;public static void main(String[] args) throws Exception{System.setIn(new FileInputStream("C:\\Users\\86153\\Desktop\\SW\\3372\\P3372_8.in"));BufferedReader reader=new BufferedReader(new InputStreamReader(System.in));StringTokenizer st=new StringTokenizer(reader.readLine());int N=Integer.parseInt(st.nextToken());//N个数字int M=Integer.parseInt(st.nextToken());//M次操作int L=1;while(L<N){L=L+L;}sum_tree=new long[2*L];tag=new long[2*L];a=new long[2*L];st=new StringTokenizer(reader.readLine());for (int i = 1; i <=N ; i++) {a[i]=Integer.parseInt(st.nextToken());}build(1,1,N);for (int i = 0; i <M ; i++) {st=new StringTokenizer(reader.readLine());int o=Integer.parseInt(st.nextToken());int a=Integer.parseInt(st.nextToken());int b=Integer.parseInt(st.nextToken());if(o==1){//将区间的数字都加Kint k=Integer.parseInt(st.nextToken());update(a,b,1,N,1,k);}else{long v=query(a,b,1,N,1);System.out.println(v);}}reader.close();}static int ls(int x){return x<<1;}static int rs(int x){return x<<1|1;}static void push_up(int p){sum_tree[p]=sum_tree[ls(p)]+sum_tree[rs(p)];}static void build(int p,int l,int r){tag[p]=0;if(l==r){sum_tree[p]=a[l];return ;}int mid=(l+r)>>1;build(ls(p),l,mid);build(rs(p),mid+1,r);push_up(p);}static void f(int p,int l,int r,long k){tag[p]=tag[p]+k;sum_tree[p]=sum_tree[p]+k*(r-l+1);}static void push_down(int p,int l,int r){int mid=(l+r)>>1;f(ls(p),l,mid,tag[p]);f(rs(p),mid+1,r,tag[p]);tag[p]=0;}static void update(long nl,long nr,int l,int r,int p,long k){if(nl<=l&&r<=nr){sum_tree[p]+=k*(r-l+1);tag[p]+=k;return ;}push_down(p,l,r);int mid=(l+r)>>1;if(nl<=mid)update(nl,nr,l,mid,ls(p),k);if(nr>mid) update(nl,nr,mid+1,r,rs(p),k);push_up(p);}static long query(long q_x,long q_y,int l,int r,int p){long res=0;if(q_x<=l&&r<=q_y)return sum_tree[p];int mid=(l+r)>>1;push_down(p,l,r);if(q_x<=mid)res+=query(q_x,q_y,l,mid,ls(p));if(q_y>mid) res+=query(q_x,q_y,mid+1,r,rs(p));return res;}
}