洛谷 P3372 线段树模板

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【分析】
splay搞yeah

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【代码】

//线段树板子(splay复习) 
#include<iostream>
#include<cstring>
#include<cstdio>
#define ll long long
#define M(a) memset(a,0,sizeof a)
#define fo(i,j,k) for(i=j;i<=k;i++)
using namespace std;
const int mxn=100005;
ll n,m,sz,root,k;
int ch[mxn][2],f[mxn],size[mxn];
ll key[mxn],sum[mxn],add[mxn],a[mxn];
inline ll read()
{
    ll x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9') {if(ch=='-') f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
    return x*f;
}
inline int get(int x)
{
    if(ch[f[x]][1]==x) return 1;return 0;
}
inline void update(int x)
{
    size[x]=size[ch[x][0]]+size[ch[x][1]]+1;
    sum[x]=sum[ch[x][0]]+sum[ch[x][1]]+key[x];
}
inline void ADD(int x,ll ad)
{
    add[x]+=ad,key[x]+=ad;
    sum[x]+=ad*size[x];
}
inline void pushdown(int x)
{
    if(x && add[x])
    {
        if(ch[x][0]) ADD(ch[x][0],add[x]);
        if(ch[x][1]) ADD(ch[x][1],add[x]);
        add[x]=0;
    }
}
inline void rotate(int x)
{
    pushdown(x);
    int fa=f[x],fafa=f[fa],which=get(x);
    ch[fa][which]=ch[x][which^1],f[ch[fa][which]]=fa;
    ch[x][which^1]=fa,f[fa]=x;
    f[x]=fafa;
    if(fafa) ch[fafa][ch[fafa][1]==fa?1:0]=x;
    update(fa),update(x);
}
inline void splay(int x,int lastfa)
{
    for(int fa;(fa=f[x])!=lastfa;rotate(x))
      if(f[fa]!=lastfa) rotate(get(x)==get(fa)?fa:x);
    if(!lastfa) root=x;
}
inline int number(int x)
{
    int now=root;
    while(1)
    {
        pushdown(now);
        if(x<=size[ch[now][0]] && ch[now][0]) now=ch[now][0];
        else 
        {
            if(x==size[ch[now][0]]+1) return now;
            x=x-size[ch[now][0]]-1;
            now=ch[now][1];
        }
    }
}
inline int build(int fa,int l,int r)
{
    if(l>r) return 0;
    int now=++sz,mid=l+r>>1;
    f[now]=fa,key[now]=sum[now]=a[mid],size[now]=1;
    ch[now][0]=build(now,l,mid-1);
    ch[now][1]=build(now,mid+1,r);
    update(now);
    return now;
}
int main()
{
    int i,j,x,y,opt;
    scanf("%lld%lld",&n,&m);
    fo(i,2,n+1) scanf("%lld",&a[i]);
    root=build(0,1,n+2);
    fo(i,1,m)
    {
        opt=read();
        if(opt==1)
        {
            scanf("%d%d%lld",&x,&y,&k);x++,y++;
            x=number(x-1),y=number(y+1);
            splay(x,0),splay(y,x);
            ADD(ch[y][0],k);
        }
        if(opt==2)
        {
            scanf("%d%d",&x,&y);x++,y++;
            x=number(x-1),y=number(y+1);
            splay(x,0),splay(y,x);
            printf("%lld\n",sum[ch[y][0]]);
        }
    }
    return 0;
}