Combine the HDU 2871 line segment tree and interval

A very comprehensive question ~ No online segment tree is used for the second test ~~

#include <iostream>#include <cstring>#include <cstdio>#include <algorithm>#define lson pos<<1#define rson pos<<1|1using namespace std;const int MAXN=50005;int blocks[MAXN*2];struct node{    int l,r;    int msum,lsum,rsum;    int lazy;    int mid()    {        return (l+r)>>1;    }};node tree[MAXN*4];inline void pushup(int pos){    tree[pos].msum=max(tree[lson].msum,tree[rson].msum);    tree[pos].lsum=tree[lson].lsum;    tree[pos].rsum=tree[rson].rsum;    tree[pos].msum=max(tree[pos].msum,tree[lson].rsum+tree[rson].lsum);    int l1=tree[lson].r-tree[lson].l+1;    int l2=tree[rson].r-tree[rson].l+1;    if(tree[lson].lsum==l1)        tree[pos].lsum+=tree[rson].lsum;    if(tree[rson].rsum==l2)        tree[pos].rsum+=tree[lson].rsum;}inline void pushdown(int pos){    if(tree[pos].lazy!=-1)    {        tree[lson].lazy=tree[pos].lazy;        tree[rson].lazy=tree[pos].lazy;        if(tree[pos].lazy==1)        {            tree[lson].lsum=tree[lson].rsum=tree[lson].msum=0;            tree[rson].lsum=tree[rson].rsum=tree[rson].msum=0;        }        else        {            tree[lson].lsum=tree[lson].rsum=tree[lson].msum=                tree[lson].r-tree[lson].l+1;            tree[rson].lsum=tree[rson].rsum=tree[rson].msum=                tree[rson].r-tree[rson].l+1;        }        tree[pos].lazy=-1;    }}void build(int l,int r,int pos){    tree[pos].l=l;    tree[pos].r=r;    if(l==r)    {        tree[pos].msum=1;        tree[pos].lsum=tree[pos].rsum=1;        tree[pos].lazy=-1;        return ;    }    int mid=tree[pos].mid();    build(l,mid,lson);    build(mid+1,r,rson);    pushup(pos);    tree[pos].lazy=-1;}void update(int l,int r,int x,int pos){    if(l==tree[pos].l&&r==tree[pos].r)    {        tree[pos].lazy=x;        if(x==0)        {            tree[pos].lsum=tree[pos].rsum=tree[pos].msum=                tree[pos].r-tree[pos].l+1;        }        else        {            tree[pos].lsum=tree[pos].rsum=tree[pos].msum=0;        }        return ;    }    pushdown(pos);    int mid=tree[pos].mid();    if(r<=mid)        update(l,r,x,lson);    else if(l>mid)        update(l,r,x,rson);    else    {        update(l,mid,x,lson);        update(mid+1,r,x,rson);    }    pushup(pos);}int query(int x,int pos){    if(tree[pos].msum<x)        return 0;    if(tree[pos].lsum>=x)        return tree[pos].l;    pushdown(pos);    if(tree[lson].msum>=x)        return query(x,lson);    else if(tree[lson].rsum+tree[rson].lsum>=x)        return tree[lson].r-tree[lson].rsum+1;    else        return query(x,rson);}int main(){    int n,m;    while(scanf("%d%d",&n,&m)!=EOF)    {        build(1,n,1);        char word[10];        int i;        int k=0;        int ff=0;        for(i=0;i<m;i++)        {            int x;            scanf("%s",word);            if(word[0]!='R')                scanf("%d",&x);            if(word[0]=='R')            {                update(1,n,0,1);                printf("Reset Now\n");                k=0;            }            else if(word[0]=='N')            {                int a=query(x,1);                if(a==0)                    printf("Reject New\n");                else                {                    printf("New at %d\n",a);                    update(a,a+x-1,1,1);                    blocks[k++]=a;                    blocks[k++]=a+x-1;                    ff=0;                }            }            else if(word[0]=='F')            {                if(ff==0)                    sort(blocks,blocks+k),ff=1;                int l=0,r=k-1;                int res;                while(l<=r)                {                    int mid=(l+r)>>1;                    if(blocks[mid]>x)                        r=mid-1;                    else                    {                        l=mid+1;                    }                }                res=l-1;                if(res==-1)                    printf("Reject Free\n");                else if(blocks[res]==x)                {                    if(res%2==0)                        l=res,r=res+1;                    else                        l=res-1,r=res;                    printf("Free from %d to %d\n",blocks[l],blocks[r]);                    update(blocks[l],blocks[r],0,1);                    for(int j=r+1;j<k;j++)                        blocks[j-2]=blocks[j];                    k=k-2;                }                else                {                    if(res%2==0)                    {                        l=res,r=res+1;                        printf("Free from %d to %d\n",blocks[l],blocks[r]);                        update(blocks[l],blocks[r],0,1);                        for(int j=r+1;j<k;j++)                            blocks[j-2]=blocks[j];                        k=k-2;                    }                    else                    {                        printf("Reject Free\n");                    }                }            }            else if(word[0]=='G')            {                if(ff==0)                    sort(blocks,blocks+k),ff=1;                if((x-1)*2>=k)                    printf("Reject Get\n");                else                    printf("Get at %d\n",blocks[(x-1)*2]);            }        }        printf("\n");    }    return 0;}