Adding New Machine ZOJ - 3540

https://vjudge.net/problem/ZOJ-3540

错误记录：

扫描线没有考虑到同一行的要删除在前，加入在后；由于用了特殊的方式所以想当然以为不需要考虑这个问题

 #include<cstdio>
 #include<algorithm>
 #include<cstring>
 #include<vector>
 #include<set>
 using namespace std;
 #define fi first
 #define se second
 #define mp make_pair
 #define pb push_back
 typedef long long ll;
 typedef unsigned long long ull;
 typedef pair<int,int> pi;
 struct Q
 {
     ll x1,y1,x2,y2;
 }q[];
 ll w,h,n,m;
 struct Q2
 {
     ll x1,x2,y,type;
 }qt[];
 ll t1[];
 bool operator<(const Q2 &a,const Q2 &b)
 {
     return a.y<b.y||(a.y==b.y&&a.type<b.type);
 }
 ll qn,ta,ans;
 set<pi> s;
 set<pi>::iterator it;
 int main()
 {
     ll i,r,tx,ty;
     while(scanf("%lld%lld%lld%lld",&w,&h,&n,&m)==)
     {
         ans=;

         for(i=;i<=n;i++)    scanf("%lld%lld%lld%lld",&q[i].x1,&q[i].y1,&q[i].x2,&q[i].y2);

         qn=;
         s.clear();s.insert(mp(-,));s.insert(mp(w+,w+));
         for(i=;i<=n;i++)
         {
             ++qn;qt[qn].x1=q[i].x1;qt[qn].x2=q[i].x2;qt[qn].y=q[i].y1;qt[qn].type=;
             ++qn;qt[qn].x1=q[i].x1;qt[qn].x2=q[i].x2;qt[qn].y=q[i].y2+;qt[qn].type=;
         }
         sort(qt+,qt+qn+);
         for(i=;i<=qn;i++)    t1[i]=qt[i].y;
         t1[]=qn;
         t1[++t1[]]=;
         t1[++t1[]]=h+;
         sort(t1+,t1+t1[]+);t1[]=unique(t1+,t1+t1[]+)-t1-;
         r=;ta=max(w-m+,0ll);
         for(i=;i<t1[];i++)
         {
             while(r+<=qn&&qt[r+].y<=t1[i])
             {
                 r++;
                 if(qt[r].type==)
                 {
                     it=s.lower_bound(mp(qt[r].x1,qt[r].x2));
                     tx=it->first;ty=(--it)->second;
                     ta-=max(tx-ty-m,0ll);
                     ta+=max(qt[r].x1-ty-m,0ll);
                     ta+=max(tx-qt[r].x2-m,0ll);
                     s.insert(mp(qt[r].x1,qt[r].x2));
                 }
                 else
                 {
                     it=s.lower_bound(mp(qt[r].x1,qt[r].x2));
                     tx=(++it)->first;--it;ty=(--it)->second;
                     ta-=max(qt[r].x1-ty-m,0ll);
                     ta-=max(tx-qt[r].x2-m,0ll);
                     ta+=max(tx-ty-m,0ll);
                     s.erase(mp(qt[r].x1,qt[r].x2));
                 }
             }
             ans+=ta*(t1[i+]-t1[i]);
         }

         qn=;
         s.clear();s.insert(mp(-,));s.insert(mp(h+,h+));
         for(i=;i<=n;i++)
         {
             ++qn;qt[qn].x1=q[i].y1;qt[qn].x2=q[i].y2;qt[qn].y=q[i].x1;qt[qn].type=;
             ++qn;qt[qn].x1=q[i].y1;qt[qn].x2=q[i].y2;qt[qn].y=q[i].x2+;qt[qn].type=;
         }
         sort(qt+,qt+qn+);
         for(i=;i<=qn;i++)    t1[i]=qt[i].y;
         t1[]=qn;
         t1[++t1[]]=;
         t1[++t1[]]=w+;
         sort(t1+,t1+t1[]+);t1[]=unique(t1+,t1+t1[]+)-t1-;
         r=;ta=max(h-m+,0ll);
         for(i=;i<t1[];i++)
         {
             while(r+<=qn&&qt[r+].y<=t1[i])
             {
                 r++;
                 if(qt[r].type==)
                 {
                     it=s.lower_bound(mp(qt[r].x1,qt[r].x2));
                     tx=it->first;ty=(--it)->second;
                     ta-=max(tx-ty-m,0ll);
                     ta+=max(qt[r].x1-ty-m,0ll);
                     ta+=max(tx-qt[r].x2-m,0ll);
                     s.insert(mp(qt[r].x1,qt[r].x2));
                 }
                 else
                 {
                     it=s.lower_bound(mp(qt[r].x1,qt[r].x2));
                     tx=(++it)->first;--it;ty=(--it)->second;
                     ta-=max(qt[r].x1-ty-m,0ll);
                     ta-=max(tx-qt[r].x2-m,0ll);
                     ta+=max(tx-ty-m,0ll);
                     s.erase(mp(qt[r].x1,qt[r].x2));
                 }
             }
             ans+=ta*(t1[i+]-t1[i]);
         }

         if(m==)    ans/=;
         printf("%lld\n",ans);
     }
     return ;
 }