poj3580 伸展树（区间翻转 区间搬移 删除结点 加入结点 成段更新）

　　好题。我做了很久，学了大牛们的区间搬移。主要的代码都有注释。

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#define INF 999999999
#define key_value ch[ch[root][1]][0]
using namespace std;
const int MAXN = 200010;
int pre[MAXN],lazy[MAXN],siz[MAXN],ch[MAXN][2],s[MAXN],key[MAXN],tot1,tot2,root,ans[MAXN];
int n,a[MAXN],rev[MAXN];//rev表示旋转 lazy标记增加的量
/****************************/
void Treavel(int x)
{
    if(x)
    {
        Treavel(ch[x][0]);
        printf("结点%2d:左儿子 %2d 右儿子 %2d 父结点 %2d size=%2d,key=%2d lazy=%2d rev=%2d ans=%2d\n",x,ch[x][0],ch[x][1],pre[x],siz[x],key[x],lazy[x],rev[x],ans[x]);
        Treavel(ch[x][1]);
    }
}
void debug()
{
    printf("root:%d\n",root);
    Treavel(root);
}
/****************************/
void Newnode(int &rt,int pa,int k)
{
    if(tot2)
        rt = s[--tot2];
    else
        rt = ++tot1;
    pre[rt] = pa;
    key[rt] = k;
    lazy[rt] = 0;
    siz[rt] = 1;
    rev[rt] = 0;
    ans[rt] = k;
    ch[rt][0] = ch[rt][1] = 0;
}
void pushup(int rt)
{
    siz[rt] = siz[ch[rt][0]] + siz[ch[rt][1]] + 1;
    ans[rt] = key[rt];
    if(ch[rt][0]) //因为是min
        ans[rt] = min(ans[rt],ans[ch[rt][0]]);
    if(ch[rt][1]) 
        ans[rt] = min(ans[rt],ans[ch[rt][1]]);
}
void pushdown(int rt)
{
    if(rev[rt]){
        rev[ch[rt][0]] ^= 1;
        rev[ch[rt][1]] ^= 1;
        swap(ch[rt][0],ch[rt][1]);
        rev[rt] = 0;
    }
    if(lazy[rt]){
        lazy[ch[rt][0]] += lazy[rt];
        lazy[ch[rt][1]] += lazy[rt];
        key[ch[rt][0]] += lazy[rt];
        key[ch[rt][1]] += lazy[rt];
        ans[ch[rt][0]] += lazy[rt];
        ans[ch[rt][1]] += lazy[rt];
        lazy[rt] = 0;
    }
}
void build(int &rt,int l,int r,int pa)
{
    if(l > r)
        return ;
    int m = (l+r)/2;
    Newnode(rt,pa,a[m]);
    build(ch[rt][0],l,m-1,rt);
    build(ch[rt][1],m+1,r,rt);
    pushup(rt);
}
void Init()
{
    tot1 = tot2 = root = 0;
    siz[root] = pre[root] = lazy[root] = key[root] = rev[root] = 0;
    ans[root] = INF;
    ch[root][0] = ch[root][1] = 0;
    Newnode(root,0,-1);
    Newnode(ch[root][1],root,-1);
    build(key_value,1,n,ch[root][1]);
    pushup(ch[root][1]);
    pushup(root);
}
//先pushdown将lazy压下去
void Rotate(int rt,int kind)
{
    pushdown(pre[rt]);
    pushdown(rt);
    int y = pre[rt];
    ch[y][!kind] = ch[rt][kind];
    pre[ch[rt][kind]] = y;
    if(pre[y]){
        ch[pre[y]][ch[pre[y]][1]==y] = rt;
    }
    pre[rt] = pre[y];
    ch[rt][kind] = y;
    pre[y] = rt;
    pushup(y);
    pushup(rt);
}
//先pushdown将lazy压下去
void splay(int rt,int goal)
{
    pushdown(rt);
    while(pre[rt] != goal)
    {
        if(pre[pre[rt]] == goal){
            pushdown(pre[rt]);
            pushdown(rt);
            Rotate(rt,ch[pre[rt]][0]==rt);
        }
        else {
            pushdown(pre[pre[rt]]);
            pushdown(pre[rt]);
            pushdown(rt);
            int y = pre[rt];
            int kind = ch[pre[y]][0]==y;
            if(ch[y][kind] == rt){
                Rotate(rt,!kind);
                Rotate(rt,kind);
            }
            else {
                Rotate(y,kind);
                Rotate(rt,kind);
            }
        }
    }
    pushup(rt);
    if(goal == 0)
        root = rt;

}
int Get_kth(int rt,int k)
{
    pushdown(rt);
    int t = siz[ch[rt][0]] + 1;
    if(t == k)
        return rt;
    else if(t > k){
        return Get_kth(ch[rt][0],k);
    }
    else {
        return Get_kth(ch[rt][1],k-t);
    }
    pushup(rt);
}
void add(int x,int y,int z)
{
    splay(Get_kth(root,x),0);
    splay(Get_kth(root,y+2),root);
    lazy[key_value] += z;
    key[key_value] += z;
    ans[key_value] += z;
    pushup(ch[root][1]);
    pushup(root);//
}
int Get_min(int rt)
{
    pushdown(rt);
    while(ch[rt][0]){
        rt = ch[rt][0];
        pushdown(rt);
    }
    return rt;
}
int Get_max(int rt)
{
    pushdown(rt);
    while(ch[rt][1]){
        rt = ch[rt][1];
        pushdown(rt);
    }
    return rt;
}
int query(int x,int y)
{
    splay(Get_kth(root,x),0);
    splay(Get_kth(root,y+2),root);
    return ans[key_value];
}
void Del(int x)
{
    splay(Get_kth(root,x),0);
    splay(Get_kth(root,x+2),root);
    pre[key_value] = 0;
    key_value = 0;
    pushup(ch[root][1]);
    pushup(root);
}
void Insert(int x,int y)
{
    splay(Get_kth(root,x+1),0);
    splay(Get_kth(root,x+2),root);
    Newnode(key_value,ch[root][1],y);
    pushup(ch[root][1]);
    pushup(root);
}
void Reverse(int x,int y)
{
    splay(Get_kth(root,x),0);
    splay(Get_kth(root,y+2),root);
    rev[key_value] ^= 1;
    pushup(ch[root][1]);
    pushup(root);
}
void Revolve(int l,int r,int t)
{
    //区间平移其实就是把区间[l,c-1],[c,r]中的[c,r]放到[l,c-1]前
    int len = r - l + 1;//取mod
    t = (t%len + len)%len;
    if(!t)return ;
    int c = r - t + 1;
    splay(Get_kth(root,c),0);
    splay(Get_kth(root,r+2),root);
    int tmp = key_value;//这里的是[c,r]的区间
    key_value = 0;
    pushup(ch[root][1]);
    pushup(root);//注意这两步 这里把key_value取0 这样主要为了取走[c,r]，所以要更新
    splay(Get_kth(root,l),0);
    splay(Get_kth(root,l+1),root);
    key_value = tmp;
    pre[key_value] = ch[root][1];
    pushup(ch[root][1]);
    pushup(root);
}
int main()
{
    int i,j;
    while(~scanf("%d",&n))
    {
        for(i=1; i<=n; i++){
            scanf("%d",&a[i]);
        }
        Init();
        int q;
        scanf("%d",&q);
        char work[10];
        //debug();
        //cout<<"test: "<<endl;
        while(q--)
        {
            scanf("%s",work);
            if(work[0] == 'A'){
                int x,y,z;
                scanf("%d%d%d",&x,&y,&z);
                add(x,y,z);
                //debug();
            }
            else if(work[0] == 'M'){
                int x,y;
                scanf("%d%d",&x,&y);
                printf("%d\n",query(x,y));
            }
            else if(work[0] == 'D'){
                int x;
                scanf("%d",&x);
                Del(x);
                //debug();
            }
            else if(work[0] == 'I'){
                int x,y;
                scanf("%d%d",&x,&y);
                Insert(x,y);
                //debug();
            }
            else if(strcmp(work,"REVERSE") == 0){
                int x,y;
                scanf("%d%d",&x,&y);
                Reverse(x,y);
                //debug();
            }
            else if(strcmp(work,"REVOLVE") == 0){
                int x,y,ft;
                scanf("%d%d%d",&x,&y,&ft);
                Revolve(x,y,ft);
                //debug();
            }
        }
    }
}