CDQ分治求不知道多少维偏序 (持续更新 ]

求三维偏序的模板 :

 //Author : 15owzLy1
 //luogu3810.cpp
 //2018 12 25      16:31:58
 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 static char buf[],*p1=buf,*p2=buf;
 inline char get_char() {
     return p1==p2&&(p2=(p1=buf)+fread(buf,,,stdin),p1==p2)?EOF:*p1++;
 }
 inline int in() {
     int x=;char c=get_char();
     while(c<''||c>'')c=get_char();
     while(c>=''&&c<='')x=(x<<)+(x<<)+(c^), c=get_char();
     return x;
 }
 template<typename T>
 inline void out(T &x) {
     int cnt=;
     static char s[];
     do s[cnt++]=x%+; while(x/=);
     while(cnt--) putchar(s[cnt]);
     putchar('\n');
 }

 const int N = (int)1e5+;
 struct Triple {
     int x, y, z, val, ans;
 }a[N], tmp[N];
 int n, k, ans[N];

 inline bool cmp(const Triple &x, const Triple &y) {
     if(x.x==y.x) return x.z==y.z?x.y<y.y:x.z<y.z;
     return x.x<y.x;
 }

 struct BinaryIndexedTree {
     int t[N<<];
     inline void insert(int p, int del) {for(;p<=k;p+=p&-p)t[p]+=del;}
     inline int ask(int p) {int ret=;for(;p;p-=p&-p)ret+=t[p];return ret;}
 }bit;

 void cdq(int l, int r) {
     if(l==r) return ;
     int mid=(l+r)>>;
     cdq(l, mid); cdq(mid+, r);
     int i=l, j=mid+, k=l;
     while(i<=mid&&j<=r)
         if(a[i].z<=a[j].z)
             bit.insert(a[i].y, a[i].val), tmp[k++]=a[i++];
         else
             a[j].ans+=bit.ask(a[j].y), tmp[k++]=a[j++];
     for(int p=j;p<=r;p++) a[p].ans+=bit.ask(a[p].y);
     for(int p=l;p<i;p++)  bit.insert(a[p].y, -a[p].val);
     if(i<=mid) std::copy(a+i, a+mid+, tmp+k);
     if(j<=r)   std::copy(a+j, a+r+, tmp+k);
     std::copy(tmp+l, tmp+r+, a+l);
 }

 int main() {
     int nn=in();
     k=in();
     for(int i=;i<=nn;i++)
         tmp[i]=(Triple){in(), in(), in(), , };

     std::sort(tmp+, tmp++nn, cmp);
     for(int i=, cnt=;i<=nn;i++, cnt++)
         if(tmp[i].x!=tmp[i+].x||tmp[i].y!=tmp[i+].y||tmp[i].z!=tmp[i+].z)
             a[++n]=tmp[i], a[n].val=cnt, cnt=;
     cdq(, n);
     for(int i=;i<=n;i++) ans[a[i].ans+a[i].val-]+=a[i].val;
     for(int i=;i<nn;i++) out(ans[i]);
     return ;
 }