poj 1177 picture 线段树

调了两天。。。最后那天晚上线段树按[1,2)写的很容易就对了。。

/*ID:autoacd1PROG:pictureLANG:C++*/#include<iostream>#include<algorithm>#include<cstring>#include<cstdio>#define MAX 21000#include<cmath>using namespace std;struct wbysr{int x1,y1,x2,y2,d;}x[10000+4],y[10000+4];int n,i,ans_x=0,ans_y=0,ori=0;int l[4*MAX],r[4*MAX],f[4*MAX],len[4*MAX];bool cmp_x(wbysr a1,wbysr a2){return (a1.y1>a2.y1)||(a1.y1==a2.y1&&a1.d>a2.d);}bool cmp_y(wbysr a1,wbysr a2){return(a1.x1>a2.x1)||(a1.x1==a2.x1&&a1.d>a2.d);}void build(int x,int la,int ra){l[x]=la;r[x]=ra;f[x]=0;len[x]=0;if(la==ra-1)  return;int mid=(la+ra)/2;build(2*x,la,mid);build(2*x+1,mid,ra);}void insert(int x,int la,int ra,int num){        if(ra<=l[x]||la>=r[x])  return;if(l[x]>=la&&r[x]<=ra&&f[x]+num>=0)  {     f[x]+=num; if(f[x]>0)            len[x]=r[x]-l[x];else         {   if(l[x]<r[x]-1)     len[x]=len[2*x]+len[2*x+1];    else      len[x]=0;         } return;    }f[2*x]+=f[x];f[2*x+1]+=f[x];f[x]=0;if(f[2*x])   len[2*x]=r[2*x]-l[2*x];/*else         {   if(l[2*x]<r[2*x]-1)     len[2*x]=len[2*2*x]+len[2*(2*x)+1];    else      len[2*x]=0;         }*/if(f[2*x+1])   len[2*x+1]=r[2*x+1]-l[2*x+1];/*else         {   if(l[2*x+1]<r[2*x+1]-1)     len[2*x+1]=len[2*(2*x+1)]+len[2*(2*x+1)+1];    else      len[(2*x+1)]=0;         }*/insert(2*x,la,ra,num);insert(2*x+1,la,ra,num);if(f[x])            len[x]=r[x]-l[x];else         len[x]=len[2*x]+len[2*x+1];return;}int main(){    {        //freopen("1.out","w",stdout);//    freopen("picture.in","r",stdin);  //  freopen("picture.out","w",stdout);  cin>>n;for(i=1;i<=2*n;i+=2) { int x1,y1,x2,y2; scanf("%d%d%d%d",&x1,&y1,&x2,&y2);   ///*    x1+=10005; x2+=10005; y2+=10005; y1+=10005;  // */  //x x[i].x1=x1; x[i].y1=y1; x[i].x2=x2;x[i].y2=y1;  x[i].d=-1;  i++; x[i].x1=x1; x[i].y1=y2; x[i].x2=x2;x[i].y2=y2;  x[i].d=1;  //y i--; y[i].x1=x1; y[i].y1=y1; y[i].x2=x1;y[i].y2=y2;  y[i].d=-1; i++;  y[i].x1=x2; y[i].y1=y1; y[i].x2=x2;y[i].y2=y2;  y[i].d=1; i--; }//x!!!    sort(x+1,x+1+n+n,cmp_x);       build(1,1,MAX+4);   for(i=1;i<=2*n;i++)          {       //cout<<"-------------------------------------------"<<i<<endl;        insert(1,x[i].x1,x[i].x2,x[i].d);                if(x[i].y1!=x[i+1].y1||x[i].d!=x[i+1].d) {    ans_x+=abs(len[1]-ori);           ori=len[1]; }         //   cout<<"___"<<x[i].x1<<' '<<x[i].x2<<' '<<x[i].d<<' '<<len[1]<<' '<<ans_x<<endl;   /*                 cout<<"-________________________________"<<endl;           for(int j=1;j<=136;j++)               cout<<j<<"   "<<l[j]<<"   "<<r[j]<<"   "<<len[j]<<"   "<<f[j]<<endl;  //  */       } //   cout<<"_____"<<ans_x<<endl;              //y!!!  memset(l,0,sizeof(l));memset(r,0,sizeof(r));memset(f,0,sizeof(f));memset(len,0,sizeof(len));          sort(y+1,y+1+n+n,cmp_y);       build(1,1,MAX+4);    for(i=1;i<=2*n;i++)          {       //cout<<"-------------------------------------------"<<i<<endl;        insert(1,y[i].y1,y[i].y2,y[i].d);           if(y[i].x1!=y[i+1].x1||y[i].d!=y[i+1].d)             {        ans_y+=abs(len[1]-ori);           ori=len[1];       }     //      cout<<"_____"<<y[i].y1<<' '<<y[i].y2<<' '<<y[i].d<<' '<<len[1]<<' '<<ans_y<<endl;               /*     cout<<"-________________________________"<<endl;         for(int j=1;j<=49;j++)              cout<<j<<"   "<<l[j]<<"   "<<r[j]<<"   "<<len[j]<<"   "<<f[j]<<endl;          */       } //   cout<<"_____"<<ans_y<<endl;       cout<<ans_x+ans_y<<endl;    }    return 0;}