51nod 1264 segment Intersection (the intersection of segments, including endpoints and partial overlap)

1264 segment intersection base time limit: 1 seconds space limit: 131072 KB score: 0 Difficulty: The base collection focuses on the two endpoints of two segments on the plane, judging if the two segments intersect (there is a common point or partial overlap is considered intersecting). If it intersects, output "Yes", otherwise output "No". Input

Line 1th: A number T, indicating the number of tests entered (1 <= T <= 1000) 2-t + 1 lines: 8 numbers per line, X1,y1,x2,y2,x3,y3,x4,y4. ( -10^8 <= xi, Yi <= 10^8) (Two endpoints of line 1 are x1,y1 | x2, y2, two endpoints of line 2 are X3,y3 | x4, Y4)

Output

Output a total of t lines, or output "No" if the intersection output is "Yes".

Input example

21 2 2 1 0 0 2 2-1 1 1 1 0 0 1-1

Output example

YesNo

Li Tao(topic Provider)

#include <iostream> #include <algorithm> #include <stdio.h> #include <string.h> #include < stdlib.h> #include <math.h> #define EPS 1e-8#define Zero (x) (((x) > 0? (x): (-X)) < EPS) using namespace std;struct point {double X, y;}; struct Line {point a b;}; Double Xmult (Point P1,point p2,point p) {return (p1.x-p.x) * (P2.Y-P.Y)-(p2.x-p.x) * (P1.Y-P.Y);} int dot_online_in (Point p,line L) {return zero (Xmult (p,l.a,l.b)) && (l.a.x-p.x) * (l.b.x-p.x) < EPS &&am P (L.A.Y-P.Y) * (L.B.Y-P.Y) < EPS;} int Dot_inline (point p1,point p2,point p3) {return zero (Xmult (P1,P2,P3));} int Same_side (point p1,point p2,line l) {return Xmult (l.a,p1,l.b) *xmult (l.a,p2,l.b) >eps;} int intersect_in (line U,line v) {if (!dot_inline (U.A,U.B,V.A) | |!dot_inline (U.A,U.B,V.B)) {return!same_side (u.a    , u.b,v) &&!same_side (v.a,v.b,u); } return dot_online_in (u.a,v) | | Dot_online_in (u.b,v) | | Dot_online_in (v.a,u) | | Dot_online_in(V.b,u);}    int main () {int T;    scanf ("%d", &t);        while (t--) {line u,v; scanf ("%lf%lf%lf%lf%lf%lf%lf%lf", &u.a.x,&u.a.y,&u.b.x,&u.b.y,&v.a.x,&v.a.y,&v.b.x,        &AMP;V.B.Y);        int flag = intersect_in (U,V);        if (flag = = 1) {printf ("yes\n");        } else {printf ("no\n"); }} return 0;}

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51nod 1264 segment Intersection (the intersection of segments, including endpoints and partial overlap)