Mayor 's posters, 선분 수, 이산 화

#include
#include
#include
#include
using namespace std;
#define N 60100
#define ls (p<<1)
#define rs (p<<1|1)
#define mid(p) (t[p].l+t[p].r>>1)

struct segmentTree{
    int l,r,v;
    int tag;
}t[N*4];

void lazy(int p){
    if (t[p].tag){
        t[ls].v=t[rs].v=t[ls].tag=t[rs].tag=t[p].tag;
        t[p].tag=0;
    }
}

void build(int l,int r,int p){
    t[p].l=l;t[p].r=r;t[p].tag=t[p].v=0;
    if (t[p].l==t[p].r)  return;
    int m=mid(p);
    build(l,m,ls);
    build(m+1,r,rs);
}

void update(int l,int r,int p,int v){
    if (l==t[p].l&&r==t[p].r){
        t[p].tag=t[p].v=v;
        return;
    }
    lazy(p);
    int m=mid(p);
    if (r<=m) {
        update(l,r,ls,v);
    }
    else if (l>m){
        update(l,r,rs,v);
    }
    else {
        update(l,m,ls,v);
        update(m+1,r,rs,v);
    }
}

int query(int pos,int p){
    if (t[p].l==t[p].r) return t[p].v;
    lazy(p);
    int m=mid(p);
    if (pos<=m){
        return query(pos,ls);
    }
    else {
        return query(pos,rs);
    }
}

int vis[N],b[N];
int n;

struct poster{
    int be,ed;
}s[N];

int discret(){
    int tn=0;
    int i;
    for(i=1;i<=n;++i){
        b[++tn]=s[i].be;
        b[++tn]=s[i].be+1;
        b[++tn]=s[i].be-1;
        b[++tn]=s[i].ed;
        b[++tn]=s[i].ed+1;
        b[++tn]=s[i].ed-1;
    }
    sort(b+1,b+tn+1);
    int ret=unique(b+1,b+tn+1)-b;
    return ret;
}

int bsch(int l,int r,int v){
    int m;
    while(l<=r){
        m=l+r>>1;
        if (b[m]==v) return m;
        else if (b[m]