分治法：三维偏序问题之CDQ分治

我怀疑那个k是用来定界限用的

 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 using namespace std;
 struct edge{
     int x,y,z,ans,cnt;
 }   a[];
 int n,i,k,num,t;
 int tr[],f[];
 int read(){
     int sum=;
     char c=getchar();
     while (c<''||c>'') c=getchar();
     while (c>=''&&c<='') {
         sum=sum*+c-'';
         c=getchar();
     }
     return sum;
 }
 bool cmp2(edge a,edge b) {
     if (a.y==b.y) return a.z<b.z;
       else return a.y<b.y;
 }
 bool cmp1(edge a,edge b) {
     if (a.x==b.x) return cmp2(a,b);
       else return a.x<b.x;
 }
 void add(int x,int y){
     while (y<=t) {
         tr[y]+=x;
         y=y+(y&(-y));
     }
 }
 int query(int y){
     int s=;
     while (y>) {
       s+=tr[y];
       y=y-(y&(-y));
     }
     return s;
 }
 void cdq(int l,int r) {
     if (l==r) return;
     int mid=(l+r)>>;
     cdq(l,mid); cdq(mid+,r);
     sort(a+l,a+mid+,cmp2);
     sort(a+mid+,a+r+,cmp2);
     int l1,t,i;
     l1=l;
     for (i=mid+;i<=r;i++){
         while (a[i].y>=a[l1].y&&l1<=mid) {
             add(a[l1].cnt,a[l1].z);
             l1++;
         }
         a[i].ans+=query(a[i].z);
     }
 //  if (l1==mid) l1++;
     for (i=l;i<=l1-;i++)
       add(-a[i].cnt,a[i].z);
 }
 int main(){
 //  freopen("1.in","r",stdin);
 //  freopen("1.out","w",stdout);
     n=read(); t=read();
     for (i=;i<=n;i++) {
            a[i].x=read();a[i].y=read();a[i].z=read();}
     sort(a+,a+n+,cmp1);
     for (i=;i<=n;) {
         k=i+;
         while (a[i].x==a[k].x&&a[i].y==a[k].y&&a[i].z==a[k].z&&k<=n) k++;
         num++;
         a[num]=a[i];
         a[num].cnt=k-i;
         i=k;
     }
     cdq(,num);
     for (i=;i<=num;i++) {
         f[a[i].ans+a[i].cnt-]+=a[i].cnt;
     }
     for (i=;i<=n-;i++)
       printf("%d\n",f[i]);
 }