#include <stdio.h>#include <math.h>#include <algorithm>#include <string.h>#include <math.h>using namespace std;const double eps = 1e-8;int sgn(double x){if(fabs(x) < eps)return 0;if(x < 0)return -1;else return 1;}struct Point{double x,y;Point(){}Point(double _x,double _y){x = _x;y = _y;}Point operator -(const Point &b)const{return Point(x - b.x,y - b.y);}double operator ^(const Point &b)const{return x*b.y - y*b.x;}double operator *(const Point &b)const{return x*b.x + y*b.y;}};struct Line{Point s,e;Line(){}Line(Point _s,Point _e){s = _s;e = _e;} pair<int,Point> operator &(const Line &b)const { Point res = s; if(sgn((s-e)^(b.s-b.e)) == 0) { if(sgn((s-b.e)^(b.s-b.e)) == 0) return make_pair(0,res); else return make_pair(1,res); } double t = ((s-b.s)^(b.s-b.e))/((s-e)^(b.s-b.e)); res.x += (e.x-s.x)*t; res.y += (e.y-s.y)*t; return make_pair(2,res); }};bool inter(Line l1,Line l2){return max(l1.s.x,l1.e.x) >= min(l2.s.x,l2.e.x) && max(l2.s.x,l2.e.x) >= min(l1.s.x,l1.e.x) && max(l1.s.y,l1.e.y) >= min(l2.s.y,l2.e.y) && max(l2.s.y,l2.e.y) >= min(l1.s.y,l1.e.y) && sgn((l2.s-l1.e)^(l1.s-l1.e))*sgn((l2.e-l1.e)^(l1.s-l1.e)) <= 0 && sgn((l1.s-l2.e)^(l2.s-l2.e))*sgn((l1.e-l2.e)^(l2.s-l2.e)) <= 0;}int main(){ int x1,y1,x2,y2,x3,y3,x4,y4; int T; Line l1,l2; scanf("%d",&T); while(T--) { scanf("%d%d%d%d%d%d%d%d",&x1,&y1,&x2,&y2,&x3,&y3,&x4,&y4); l1 = Line(Point(x1,y1),Point(x2,y2)); l2 = Line(Point(x3,y3),Point(x4,y4)); if(sgn(l1.s.y-l1.e.y)==0 || sgn(l2.s.y-l2.e.y) == 0) { printf("0.00n"); continue; } if(sgn(l1.s.y-l1.e.y) < 0)swap(l1.s,l1.e); if(sgn(l2.s.y-l2.e.y) < 0)swap(l2.s,l2.e); if(inter(l1,l2) == false) { printf("0.00n"); continue; } if(inter(Line(l1.s,Point(l1.s.x,100000)),l2) ) { printf("0.00n"); continue; } if(inter(Line(l2.s,Point(l2.s.x,100000)),l1) ) { printf("0.00n"); continue; } pair<int,Point>pr; pr = l1 & l2; Point p = pr.second; double ans1; pr = l1 & Line(Point(100000,l2.s.y),l2.s); Point p1 = pr.second; ans1 = fabs( (l2.s-p)^(p1-p) )/2; double ans2; pr = l2 & Line(Point(100000,l1.s.y),l1.s); Point p2 = pr.second; ans2 = fabs( (l1.s-p)^(p2-p) )/2; printf("%.2lfn",min(ans1,ans2)); } return 0;}
