zoj2107——Quoit Design

最近点对。不过，数据比较强，需对Y排序。

不断tle，直到重敲一遍代码才A！

#include<iostream>#include<cstdio>#include<algorithm>#include<cmath>using namespace std;#define maxcost 1e100#define maxn 100005class point{public:double x,y;};point p[maxn];bool cmp(point a,point b){if(a.x <b.x ) return true;return false;}int y[maxn];bool cmpy(int a,int b){if(p[a].y<p[b].y) return true;return false;}double dist(point a,point b){return sqrt((a.x-b.x )*(a.x-b.x )+(a.y-b.y )*(a.y-b.y));}double min_dis(int left,int right){int i,j;double minlen=maxcost,resultl,resultr;if(right-left>2){int mid=(left+right)>>1;resultl=min_dis(left,mid);resultr=min_dis(mid+1,right);minlen=resultl<resultr?resultl:resultr;int len=0;for(i=mid;i>=left&&p[i].x+minlen>p[mid].x ;i--)y[++len]=i;for(i=mid+1;i<=right&&p[mid].x +minlen>p[i].x ;i++)y[++len]=i;sort(y+1,y+len+1,cmpy);for(i=1;i<len;i++)for(j=i+1;j<=len;j++){if(p[y[j]].y -p[y[i]].y>minlen) break;double dis=dist(p[y[j]],p[y[i]]);minlen=dis<minlen?dis:minlen;}}else {double dis;for(i=left;i<right;i++)for(j=i+1;j<=right;j++){dis=dist(p[i],p[j]);minlen=minlen<dis?minlen:dis;}}return minlen;}int main(){int n,i;while(cin>>n&&n){for(i=0;i<n;i++)scanf("%lf%lf",&p[i].x,&p[i].y);sort(p,p+n,cmp);double result=min_dis(0,n-1);printf("%.2f/n",result/2);}return 0;}