LA 3662 Another Minimum Spanning Tree (曼哈顿距离最小生成树 模板)

题目大意：

曼哈顿最小距离生成树

算法讨论：

同上。

这回的模板真的准了。

 #include <iostream>
 #include <cstring>
 #include <cstdlib>
 #include <algorithm>
 #include <cstdio>
 using namespace std;
 const int N =  + ;
 const int M = N * ;
 typedef long long ll;
 const ll oo = 100000000000000LL;

 int n, etot;
 ll W = , c[N];
 int fa[N], id[N];
 int A[N], B[N];

 struct Point{
     int x, y, id;
     bool operator < (const Point &a)const {
         if(a.x == x) return y < a.y;
         return x < a.x;
     }
 }p[N];

 struct Edge{
     int from, to;
     ll dis;
     bool operator < (const Edge &a)const {
         return dis < a.dis;
     }
 }e[M];

 int find(int x){return fa[x] == x ? x : fa[x] = find(fa[x]);}
 void update(int x, ll val, int pos){
     for(int i = x; i > ; i -= (i&(-i))){
         if(val < c[i]){
             c[i] = val;
             id[i] = pos;
         }
     }
 }
 int query(int pos, int up){
     int res = -;
     ll val = oo;
     for(int i = pos; i <= up; i += (i&(-i))){
         if(c[i] < val){
             val = c[i];
             res = id[i];
         }
     }
     return res;
 }
 void MST(){
     int up;
     for(int dir = ; dir <= ; ++ dir){
         if(dir %  == )
             for(int i = ; i <= n; ++ i)
                 swap(p[i].x, p[i].y);
         else if(dir == )
             for(int i = ; i <= n; ++ i)
                 p[i].x = -p[i].x;
         sort(p + , p + n + );
         for(int i = ; i <= n; ++ i) A[i] = B[i] = (int) p[i].y - p[i].x;
         sort(B + , B + n + );
         up = unique(B + , B + n + ) - B - ;

         for(int i = ; i <= up; ++ i){
             c[i] = oo; id[i] = -;
         }

         for(int i = n; i >= ; -- i){
             A[i] = lower_bound(B + , B + up + , A[i]) - B;
             int np = query(A[i], up);
             if(np != -){
                 ++ etot;
                 e[etot].from = p[i].id;
                 e[etot].to = p[np].id;
                 e[etot].dis = abs(p[i].x - p[np].x) + abs(p[i].y - p[np].y);
             }
             update(A[i], p[i].x + p[i].y, i);
         }
     }

     int have = ;
     sort(e + , e + etot + );
     for(int i = ; i <= n; ++ i) fa[i] = i;
     for(int i = ; i <= etot; ++ i){
         int fx = find(e[i].from), fy = find(e[i].to);
         if(fx != fy){
             fa[fx] = fy;
             ++ have;
             W += e[i].dis;
             if(have == n-) break;
         }
     }
 }

 int main(){
     int cnt = ;
     while(scanf("%d", &n) && n){
         ++ cnt; etot = ;
         for(int i = ; i <= n; ++ i){
             scanf("%d%d", &p[i].x, &p[i].y);
             p[i].id = i;
         }
         W = ;
         MST();
         printf("Case %d: Total Weight = %lld\n", cnt, W);
     }
     return ;
 }

LA 3662