CDQ分治求不知道多少维偏序 (持续更新 ]
求三维偏序的模板 :
1 //Author : 15owzLy1 2 //luogu3810.cpp 3 //2018 12 25 16:31:58 4 #include <cstdio> 5 #include <cstring> 6 #include <algorithm> 7 static char buf[1000001],*p1=buf,*p2=buf; 8 inline char get_char() { 9 return p1==p2&&(p2=(p1=buf)+fread(buf,1,1000000,stdin),p1==p2)?EOF:*p1++; 10 } 11 inline int in() { 12 int x=0;char c=get_char(); 13 while(c<'0'||c>'9')c=get_char(); 14 while(c>='0'&&c<='9')x=(x<<1)+(x<<3)+(c^48), c=get_char(); 15 return x; 16 } 17 template<typename T> 18 inline void out(T &x) { 19 int cnt=0; 20 static char s[20]; 21 do s[cnt++]=x%10+48; while(x/=10); 22 while(cnt--) putchar(s[cnt]); 23 putchar('\n'); 24 } 25 26 const int N = (int)1e5+5; 27 struct Triple { 28 int x, y, z, val, ans; 29 }a[N], tmp[N]; 30 int n, k, ans[N]; 31 32 inline bool cmp(const Triple &x, const Triple &y) { 33 if(x.x==y.x) return x.z==y.z?x.y<y.y:x.z<y.z; 34 return x.x<y.x; 35 } 36 37 struct BinaryIndexedTree { 38 int t[N<<1]; 39 inline void insert(int p, int del) {for(;p<=k;p+=p&-p)t[p]+=del;} 40 inline int ask(int p) {int ret=0;for(;p;p-=p&-p)ret+=t[p];return ret;} 41 }bit; 42 43 void cdq(int l, int r) { 44 if(l==r) return ; 45 int mid=(l+r)>>1; 46 cdq(l, mid); cdq(mid+1, r); 47 int i=l, j=mid+1, k=l; 48 while(i<=mid&&j<=r) 49 if(a[i].z<=a[j].z) 50 bit.insert(a[i].y, a[i].val), tmp[k++]=a[i++]; 51 else 52 a[j].ans+=bit.ask(a[j].y), tmp[k++]=a[j++]; 53 for(int p=j;p<=r;p++) a[p].ans+=bit.ask(a[p].y); 54 for(int p=l;p<i;p++) bit.insert(a[p].y, -a[p].val); 55 if(i<=mid) std::copy(a+i, a+mid+1, tmp+k); 56 if(j<=r) std::copy(a+j, a+r+1, tmp+k); 57 std::copy(tmp+l, tmp+r+1, a+l); 58 } 59 60 int main() { 61 int nn=in(); 62 k=in(); 63 for(int i=1;i<=nn;i++) 64 tmp[i]=(Triple){in(), in(), in(), 0, 0}; 65 66 std::sort(tmp+1, tmp+1+nn, cmp); 67 for(int i=1, cnt=1;i<=nn;i++, cnt++) 68 if(tmp[i].x!=tmp[i+1].x||tmp[i].y!=tmp[i+1].y||tmp[i].z!=tmp[i+1].z) 69 a[++n]=tmp[i], a[n].val=cnt, cnt=0; 70 cdq(1, n); 71 for(int i=1;i<=n;i++) ans[a[i].ans+a[i].val-1]+=a[i].val; 72 for(int i=0;i<nn;i++) out(ans[i]); 73 return 0; 74 }
