2648: SJY摆棋子

2648: SJY摆棋子

https://www.lydsy.com/JudgeOnline/problem.php?id=2648

分析：　　　

　　k-d tree 模板题。

代码：

 #include<bits/stdc++.h>
 using namespace std;
 typedef long long LL;
 
 inline int read() {
     int x=,f=;char ch=getchar();for(;!isdigit(ch);ch=getchar())if(ch=='-')f=-;
     for (;isdigit(ch);ch=getchar())x=x*+ch-'';return x*f;
 }
 
 const int N = ;
 const int DIM = ;
 const int INF = 1e9;
 
 #define lc T[rt].ch[0]
 #define rc T[rt].ch[1]
 
 struct Point {
     int x[];
     Point() {x[] = ,x[] = ;}
     Point(int a,int b) {x[] = a,x[] = b;}
 }P[N];
 struct KD_Tree {
     int ch[],mn[],mx[];
     Point p;
 }T[N<<];
 int Cur,CntNode,Ans,Root;
 
 inline bool cmp(Point a,Point b) {
     return a.x[Cur] < b.x[Cur];
 }
 inline void pushup(int rt) {
     for (int i=; i<DIM; ++i) {
         if (lc) T[rt].mn[i] = min(T[rt].mn[i],T[lc].mn[i]), T[rt].mx[i] = max(T[rt].mx[i],T[lc].mx[i]);
         if (rc) T[rt].mn[i] = min(T[rt].mn[i],T[rc].mn[i]), T[rt].mx[i] = max(T[rt].mx[i],T[rc].mx[i]); // -- rc - lc
     }
 }
 inline void NewNode(int rt,Point p) {
     T[rt].p = p;
     T[rt].mn[] = T[rt].mx[] = p.x[];
     T[rt].mn[] = T[rt].mx[] = p.x[];
 }
 int build(int l,int r,int cd) { // cd -- cur dimensions
     if (l > r) return ;
     int m = (l + r) >> ,rt = m;
     Cur = cd; nth_element(P+l, P+m, P+r+, cmp);
     NewNode(rt,P[m]);
     lc = build(l, m-, cd^);
     rc = build(m+, r, cd^);
     pushup(rt);
     return rt;
 }
 void Insert(Point p,int &rt,int cd) {
     if (!rt) {
         NewNode(rt = ++CntNode,p);return ;
     }
     if (p.x[cd] <= T[rt].p.x[cd]) Insert(p, lc, cd^);
     else Insert(p, rc, cd^);
     pushup(rt);
 }
 inline int dist(Point a,KD_Tree b) {
     int dis = ;
     if (a.x[] < b.mn[]) dis += b.mn[] - a.x[];
     if (a.x[] > b.mx[]) dis += a.x[] - b.mx[];
     if (a.x[] < b.mn[]) dis += b.mn[] - a.x[];
     if (a.x[] > b.mx[]) dis += a.x[] - b.mx[];
     return dis;
 }
 inline int dis(Point a,Point b) {
     return abs(a.x[] - b.x[]) + abs(a.x[] - b.x[]);
 }
 void query(Point p,int rt) {
     Ans = min(Ans,dis(p,T[rt].p)); // -- !!
     int dl = lc ? dist(p,T[lc]) : INF;
     int dr = rc ? dist(p,T[rc]) : INF;
     if (dl < dr) {
         if (dl < Ans) query(p,lc);
         if (dr < Ans) query(p,rc);
     }
     else {
         if (dr < Ans) query(p,rc);
         if (dl < Ans) query(p,lc);
     }
 }
 int main() {
     int n = read(),m = read();
     CntNode = n; // --- !!!
     for (int i=; i<=n; ++i)
         P[i].x[] = read(),P[i].x[] = read();
     Root = build(,n,);
     while (m--) {
         int opt = read(),x = read(),y = read();
         if (opt == ) Insert(Point(x,y),Root,);
         else {
             Ans = INF;
             query(Point(x,y),Root);
             printf("%d\n",Ans);
         }
     }
     return ;
 }

luogu上需要拍扁重构，否则会T，而bzoj上拍扁重构却不如不拍扁重构跑得快

 #include<bits/stdc++.h>
 using namespace std;
 typedef long long LL;
 
 inline int read() {
     int x=,f=;char ch=getchar();for(;!isdigit(ch);ch=getchar())if(ch=='-')f=-;
     for (;isdigit(ch);ch=getchar())x=x*+ch-'';return x*f;
 }
 
 const int N = ;
 const int DIM = ;
 const int INF = 1e9;
 
 #define alpha 0.75
 #define lc T[rt].ch[0]
 #define rc T[rt].ch[1]
 
 struct Point {
     int x[];
     Point() {x[] = ,x[] = ;}
     Point(int a,int b) {x[] = a,x[] = b;}
 }P[N<<];
 struct KD_Tree {
     int ch[],mn[],mx[],sz;
     Point p;
 }T[N<<];
 int sk[N],Top,Cur,CntNode,Ans,Root;
 
 inline bool cmp(Point a,Point b) {
     return a.x[Cur] < b.x[Cur];
 }
 inline void pushup(int rt) {
     T[rt].sz = T[lc].sz + T[rc].sz + ; //-- +1！！！
     for (int i=; i<DIM; ++i) {
         if (lc) T[rt].mn[i] = min(T[rt].mn[i],T[lc].mn[i]), T[rt].mx[i] = max(T[rt].mx[i],T[lc].mx[i]);
         if (rc) T[rt].mn[i] = min(T[rt].mn[i],T[rc].mn[i]), T[rt].mx[i] = max(T[rt].mx[i],T[rc].mx[i]);
     }
 }
 inline void NewNode(int &rt,Point p) {
     rt = Top ? sk[Top--] : ++CntNode;
     T[rt].p = p;
     T[rt].sz = ; // --！！！
     T[rt].mn[] = T[rt].mx[] = p.x[];
     T[rt].mn[] = T[rt].mx[] = p.x[];
 }
 int build(int l,int r,int cd) { // cd -- cur dimensions
     if (l > r) return ;
     int m = (l + r) >> ,rt;
     Cur = cd; nth_element(P+l, P+m, P+r+, cmp);
     NewNode(rt,P[m]);
     lc = build(l, m-, cd^);
     rc = build(m+, r, cd^);
     pushup(rt);
     return rt;
 }
 void dfs(int rt,int num) {
     if (lc) dfs(lc, num);
     P[num+T[lc].sz+] = T[rt].p, sk[++Top] = rt;
     if (rc) dfs(rc, num+T[lc].sz+);
 }
 inline void check(int &rt,int cd) {
     if (alpha * T[rt].sz < T[lc].sz || alpha * T[rt].sz < T[rc].sz) {
         dfs(rt, );
         rt = build(, T[rt].sz, cd);
     }
 }
 void Insert(Point p,int &rt,int cd) {
     if (!rt) {
         NewNode(rt,p);return ;
     }
     if (p.x[cd] <= T[rt].p.x[cd]) Insert(p, lc, cd^);
     else Insert(p, rc, cd^);
     pushup(rt);check(rt,cd);
 }
 inline int dist(Point a,KD_Tree b) {
     int dis = ;
     if (a.x[] < b.mn[]) dis += b.mn[] - a.x[];
     if (a.x[] > b.mx[]) dis += a.x[] - b.mx[];
     if (a.x[] < b.mn[]) dis += b.mn[] - a.x[];
     if (a.x[] > b.mx[]) dis += a.x[] - b.mx[];
     return dis;
 }
 inline int dis(Point a,Point b) {
     return abs(a.x[] - b.x[]) + abs(a.x[] - b.x[]);
 }
 void query(Point p,int rt) {
     Ans = min(Ans,dis(p,T[rt].p)); // -- !!
     int dl = lc ? dist(p,T[lc]) : INF;
     int dr = rc ? dist(p,T[rc]) : INF;
     if (dl < dr) {
         if (dl < Ans) query(p,lc);
         if (dr < Ans) query(p,rc);
     }
     else {
         if (dr < Ans) query(p,rc);
         if (dl < Ans) query(p,lc);
     }
 }
 int main() {
     int n = read(),m = read();
     for (int i=; i<=n; ++i)
         P[i].x[] = read(),P[i].x[] = read();
     Root = build(,n,);
     while (m--) {
         int opt = read(),x = read(),y = read();
         if (opt == ) Insert(Point(x,y),Root,);
         else {
             Ans = INF;
             query(Point(x,y),Root);
             printf("%d\n",Ans);
         }
     }
     return ;
 }