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同样是二分+DLX即可。
#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <cmath> #define LL __int64 using namespace std; const int maxn=3800; const int maxc=65; const int maxr=65; const int inf=0x3f3f3f3f; const double rinf=1e10; int L[maxn], R[maxn], D[maxn], U[maxn], C[maxn]; int S[maxc], H[maxr], size; int N,M,K; struct City{ LL x,y; }cities[maxr]; struct Radar{ int x,y; }radar[maxc]; LL map[65][65]; ///²»ÐèÒªSÓò void Link(int r, int c) { S[c]++; C[size]=c; U[size]=U[c]; D[U[c]]=size; D[size]=c; U[c]=size; if(H[r]==-1) H[r]=L[size]=R[size]=size; else { L[size]=L[H[r]]; R[L[H[r]]]=size; R[size]=H[r]; L[H[r]]=size; } size++; } void remove(int c){ for (int i=D[c]; i!=c; i=D[i]) L[R[i]]=L[i], R[L[i]]=R[i]; } void resume(int c){ for (int i=U[c]; i!=c; i=U[i]) L[R[i]]=R[L[i]]=i; } int h(){///Óþ«È·¸²¸ÇÈ¥¹ÀËã¼ôÖ¦ int ret=0; bool vis[maxc]; memset (vis, false, sizeof(vis)); for (int i=R[0]; i; i=R[i]) { if(vis[i])continue; ret++; vis[i]=true; for (int j=D[i]; j!=i; j=D[j]) for (int k=R[j]; k!=j; k=R[k]) vis[C[k]]=true; } return ret; } int ans; bool Dance(int k){ int t=h(); if(t+k>M) return false; //¸ù¾Ý¾ßÌåÎÊÌâÑ¡ÔñÏÞÖÆËÑË÷Éî¶È»òÖ±½ÓÇó½â¡£ A*Ëã·¨£¬´Ë´¦Ö»Çó×îÓŽâ if(!R[0]){ return true; } int c=R[0]; for (int i=R[0]; i; i=R[i]) if(S[i]<S[c])c=i; for (int i=D[c]; i!=c; i=D[i]){ remove(i); for (int j=R[i]; j!=i; j=R[j]) remove(j); if(Dance(k+1)) return true; for (int j=L[i]; j!=i; j=L[j]) resume(j); resume(i); } return false; } void initL(int x){///col is 1~x,row start from 1 // ans=inf; for (int i=0; i<=x; ++i){ S[i]=0; D[i]=U[i]=i; L[i+1]=i; R[i]=i+1; }///¶ÔÁбíÍ·³õʼ»¯ R[x]=0; size=x+1;///ÕæÕýµÄÔªËØ´Óm+1¿ªÊ¼ memset (H, -1, sizeof(H)); ///markÿ¸öλÖõÄÃû×Ö } LL dabs(LL a){ if(a<0) return -a; return a; } LL dist(int i,int j){ return (dabs(cities[i].x-cities[j].x)+dabs(cities[i].y-cities[j].y)); } void BuildLink(LL r){ for(int i=1;i<=N;i++){ for(int j=1;j<=N;j++){ if(map[i][j]<=r) Link(i,j); } } } void bin(){ LL Ans; LL l=0,r=20000000050ll,m; ans=inf; while(l<=r){ m=(l+r)/2ll; ans=inf; initL(N); BuildLink(m); if(Dance(0)) { Ans=m; r=m-1; } else l=m+1; } printf("%I64d\n",Ans); } int main(){ int T,t=0; scanf("%d",&T); while(T--){ scanf("%d%d",&N,&M); for(int i=1;i<=N;i++) scanf("%I64d%I64d",&cities[i].x,&cities[i].y); for(int i=1;i<=N;i++){ for(int j=1;j<=N;j++){ map[i][j]=dist(i,j); // cout<<map[i][j]<<" "; } // cout<<endl; } printf("Case #%d: ",++t); /* if(M==0){ cout<<"Yes"<<endl; int Ans=inf; for(int i=2;i<=N;i++){ if(map[1][i]<Ans) Ans=map[1][i]; } printf("%d\n",Ans); } else*/ bin(); } return 0; }
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原文地址:http://www.cnblogs.com/jie-dcai/p/4345666.html