hdu2871 线段树之空间动态存储模拟

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昨天晚上分析了一个多小时，晚上敲代码的时候卡住了，后来头脑清醒了才发现自己想复杂了，敲的虽然有点纠结，但整体还是很顺利的，只是又犯了个小错误调了半小时，烦~~~

维护左中右0连续最大值(lc,mc,rc),区间所属模块(block)以及模块左端点数(num).

ACcode:

#include<stdio.h>#include<iostream>using namespace std;const int size=55555;struct Node{       int l,r;       int lc,mc,rc;       int num,block,lazy;       }tre[size<<2];struct Block{       int s,e;}ck[size<<1];int top;int s,e;int Max(int a1,int a2) { return a1>a2?a1:a2; }void clc(int rt){     tre[rt].num=tre[rt].block=0;      tre[rt].lc=tre[rt].mc=tre[rt].rc=tre[rt].r-tre[rt].l+1;}void build(int rt,int l,int r){     tre[rt].l=l; tre[rt].r=r;     tre[rt].lazy=-1; clc(rt);     if (l==r) return ;          int m=(l+r)>>1;     build(rt<<1,l,m);     build(rt<<1|1,m+1,r);}void PushDown(int rt){     if (tre[rt].lazy>=0)     {        int v=tre[rt].lazy;        int r1=rt<<1,r2=r1|1;        int k=tre[rt].l+tre[rt].r;        int ls=k-(k>>1),rs=k>>1;        if (v)        {           tre[r1].lc=tre[r1].mc=tre[r1].rc=0;           tre[r2].lc=tre[r2].mc=tre[r2].rc=0;           tre[r1].block=tre[r2].block=tre[rt].block;           tre[r1].num=tre[rt].num;           tre[r2].num=tre[rt].block=0;        }        else        {            clc(r1);            clc(r2);        }        tre[r1].lazy=tre[r2].lazy=tre[rt].lazy;        tre[rt].lazy=-1;     }     }void PushUp(int rt){     int r1=rt<<1,r2=r1|1;     tre[rt].num=tre[r1].num+tre[r2].num;     tre[rt].lc=tre[r1].lc;     if (tre[r1].lc==(tre[r1].r-tre[r1].l+1)) tre[rt].lc+=tre[r2].lc;     tre[rt].rc=tre[r2].rc;     if (tre[r2].rc==(tre[r2].r-tre[r2].l+1)) tre[rt].rc+=tre[r1].rc;     tre[rt].mc=Max(tre[r1].rc+tre[r2].lc,Max(tre[r1].mc,tre[r2].mc));}void update(int rt,int l,int r,int L,int R,int v){     if (L<=l&&r<=R)     {        if (v)        {            tre[rt].lc=tre[rt].mc=tre[rt].rc=0;            tre[rt].num=(L==l)?1:0;            tre[rt].block=v;        }        else        {            clc(rt);        }        tre[rt].lazy=v;        return ;     }     if (l==r) return ;     PushDown(rt);     int m=(l+r)>>1;     if (L<=m) update(rt<<1,l,m,L,R,v);     if (R>m)  update(rt<<1|1,m+1,r,L,R,v);     PushUp(rt);}int querynew(int rt,int l,int r,int v){    if (l==r) return r;    PushDown(rt);    int m=(l+r)>>1,pos;    if (tre[rt<<1].mc>=v) pos=querynew(rt<<1,l,m,v);    else if ((tre[rt<<1].rc+tre[rt<<1|1].lc)>=v)  pos=m-tre[rt<<1].rc+1;    else  pos=querynew(rt<<1|1,m+1,r,v);    return pos;}int queryfree(int rt,int l,int r,int v){     if (tre[rt].lazy>=0) return tre[rt].lazy;     if (l==r) return tre[rt].block;     PushDown(rt);     int m=(l+r)>>1,tmp;     if (v<=m) tmp=queryfree(rt<<1,l,m,v);     else tmp=queryfree(rt<<1|1,m+1,r,v);     return tmp;}int queryget(int rt,int l,int r,int v){    if (l==r) return tre[rt].block;    PushDown(rt);    int m=(l+r)>>1,tmp;    if (v<=tre[rt<<1].num) tmp=queryget(rt<<1,l,m,v);    else tmp=queryget(rt<<1|1,m+1,r,v-tre[rt<<1].num);    return tmp;}int main(){    int n,q,x,pos;    char op[55];    while (~scanf("%d %d",&n,&q))    {          build(1,1,n);           top=0;          while (q--)          {                scanf("%s",op);                if (op[0]=='N')                {                   scanf("%d",&x);                    if (tre[1].mc<x) printf("Reject New\n");                   else                   {                       pos=querynew(1,1,n,x);                       ck[++top].s=pos;                       ck[top].e=pos+x-1;                       printf("New at %d\n",pos);                       update(1,1,n,pos,pos+x-1,top);                   }                }                else if (op[0]=='F')                {                     scanf("%d",&x);                     pos=queryfree(1,1,n,x);                     if (!pos) printf("Reject Free\n");                     else printf("Free from %d to %d\n",ck[pos].s,ck[pos].e);                     update(1,1,n,ck[pos].s,ck[pos].e,0);                     ck[pos].s=ck[pos].e=-1;                }                else if (op[0]=='G')                {                     scanf("%d",&x);                     if (tre[1].num<x) printf("Reject Get\n");                     else                     {                                                  pos=queryget(1,1,n,x);                             printf("Get at %d\n",ck[pos].s);                      }                }                else                {                    clc(1); tre[1].lazy=0;                    printf("Reset Now\n");                  }               }          puts("");            }    return 0;   }