Bzoj 1500 维护数列

区间信息封装起来重载加法还是很劲的

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具体见代码嗯

#include<bits/stdc++.h>using namespace std;struct Info{    int size;    int lmax,rmax,sum,value;    Info(int val = 0){        size = 1;        lmax = rmax = sum = value = val;    }    void setIt(int val){        sum = val * size;        value = lmax = rmax = max(val,sum);    }    void revIt(){        swap(lmax,rmax);    }};Info operator + (const Info & L,const Info & R){    Info ret;    ret.size = L.size + R.size;    ret.sum = L.sum + R.sum;    ret.lmax = max(L.lmax,L.sum+R.lmax);    ret.rmax = max(R.rmax,R.sum+L.rmax);    ret.value = max(max(L.value,R.value),L.rmax+R.lmax);    return ret;}const int maxn = 552345;struct Node{    int son[2],fa;    int set, flp;    bool lazy;    int v;    Info info;    int & l(){return son[0];}    int & r(){return son[1];}    Node(int val=0){        l() = r() = fa = -1;        v = val;        info = Info(val);        set = flp = 0;        lazy = false;    }    void setIt(int val){        v = val;        set = val;        lazy = true;        info.setIt(val);    }    void revIt(){        flp ^= 1;        swap(l(),r());        info.revIt();    }    void maintain();    void push_down();}node[maxn];void Node::push_down(){    if(lazy){        if(l()!=-1) node[l()].setIt(set);         if(r()!=-1) node[r()].setIt(set);         set = 0;        lazy = false;    }    if(flp){        if(l()!=-1) node[l()].revIt();        if(r()!=-1) node[r()].revIt();        flp = 0;    }}void Node::maintain(){    info = Info(v);    if(l()!=-1) info = node[l()].info + info;    if(r()!=-1) info = info + node[r()].info;}int ori(int st){    int fa = node[st].fa;    if(fa==-1) return -1;    return st == node[fa].r();}void setc(int st,int sn,int d){    if(st != -1){        node[st].son[d] = sn;        node[st].maintain();    }    if(sn != -1) node[sn].fa = st;}void zg(int x){    int st = node[x].fa,p = -1;    node[st].push_down();    node[x].push_down();    int d = ori(x),dst = ori(st);    if(st!=-1) p=node[st].fa;    setc(st,node[x].son[d^1],d);    setc(x,st,d^1);    setc(p,x,dst);}int root;#define f(x) (node[x].fa)void splay(int x,int fa=-1){    while(f(x) != fa){        if(f(f(x)) == fa) zg(x);        else{           if(ori(x)==ori(f(x))) zg(f(x));           else zg(x);           zg(x);        }    }    if(fa==-1) root = x;}int arr[maxn],nex[maxn];int head,tail;void init(){    for(int i=0;i<maxn;i++){        nex[i] = i+1;    }    head = 0,tail = maxn - 1;    nex[tail] = -1;}int newNode(int v){    int ret = head;    head = nex[head];    node[ret] = Node(v);    return ret;}void deleteNode(int st){    if(st == -1) return;    deleteNode(node[st].l());    deleteNode(node[st].r());    nex[tail] = st;    tail = st;}int build(int l,int r){    if(l>r) return -1;    int m = (l + r) >> 1;    int st = newNode(arr[m]);    setc(st,build(l,m-1),0);    setc(st,build(m+1,r),1);    return st;}int build(int n){    return build(0,n+1);}int getid(int v,int st){    node[st].push_down();    int l = node[st].l();    int lsize = 1 + (l==-1?0:node[l].info.size);    if(v == lsize) return st;    int d = v > lsize;    if(d) v -= lsize;    return getid(v,node[st].son[d]);}int getseg(int l,int r){    l--,r++;    l = getid(l+1,root),r = getid(r+1,root);    splay(r),splay(l,r);    return node[l].r();}void segMaintain(int pos){    node[node[root].l()].maintain();    node[root].maintain();}int main(){    int n,m;    while(~scanf("%d %d",&n,&m)){        init();        for(int i=1;i<=n;i++){            scanf("%d",&arr[i]);        }        char order[10];        root = build(n);        int pos,tot;        int x;        while(m--){            scanf("%s",order);            if(*order == 'I'){ //insert                scanf("%d %d",&pos,&tot);                if(tot==0) continue;                for(int i=1;i<=tot;i++){                    scanf("%d",&arr[i]);                }                int neo = build(1,tot);                 int l = getid(pos+1,root),r = getid(pos+2,root);                splay(r),splay(l,r);                setc(l,neo,1);                node[root].maintain();            }            else if(*order == 'M' && order[2] == 'X'){ //max sum                int sizer = node[root].info.size-2;                printf("%d\n",node[getseg(1,sizer)].info.value);            }            else{                scanf("%d %d",&pos,&tot);                pos = getseg(pos,pos+tot-1);                if(*order == 'D'){ //delete                    deleteNode(pos);                    node[f(pos)].r()=-1;                    segMaintain(pos);                }                if(*order == 'M'){ //make_same                    scanf("%d",&x);                    node[pos].setIt(x);                    segMaintain(pos);                }                if(*order == 'R'){ //reverse                    node[pos].revIt();                    segMaintain(pos);                }                if(*order == 'G'){ //get_sum                    if(tot == 0){                        puts("0");                        continue;                   }                    printf("%d\n",node[pos].info.sum);                }            }        }    }    return 0;}

打set标记的时候没有另外开一个lazy来标记是否有set标记WA到死QAQ