Hihocoder 1040 (Rectangle judging)

Topic Link: Portal

The main topic: give you four line segments, to determine whether to surround an area greater than 0 rectangle, can output Yes, cannot output no

Topic Ideas:

A valid four line segment should meet

1. There should be four different points

2. The slope of the line segment is divided into two groups, the same group within the group is different

3. If a line with a slope of 0 or a non-existent slope is to be ==-1, the product of the line with different slope will be seen. "YES": "NO"

#include <iostream>#include<cstdio>#include<cstdlib>#include<cmath>#include<algorithm>#include<cstring>#include<stack>#include<cctype>#include<queue>#include<string>#include<vector>#include<Set>#include<map>#include<climits>#defineLson Root<<1,l,mid#defineRson Root<<1|1,mid+1,r#defineFi first#defineSe Second#definePing (x, y) ((x-y) * (x-y))#defineMST (x, y) memset (x,y,sizeof (x))#defineMCP (x, y) memcpy (x,y,sizeof (y))using namespacestd;#defineGamma 0.5772156649015328606065120#defineMOD 1000000007#defineINF 0x3f3f3f3f#defineN 200005#defineMAXN 1050typedef pair<int,int>Pii;typedefLong LongLL;intn,m;structnode{intx, y; BOOL operator< (ConstNode&a)Const{        if(x==a.x)returny<a.y; returnx<a.x; }}node[4][2];map&LT;PII,int>M;///determine the number of verticesDoublek[5];///SlopeintMain () {inti,j,group,x,y,v;  while(SCANF ("%d", &group)! =EOF) {         while(group--) {m.clear ();  for(i=0; i<=3;++i) {scanf ("%d%d", &node[i][0].x,&node[i][0].y); scanf ("%d%d", &node[i][1].x,&node[i][1].y); Sort (Node[i],node[i]+2); }            intnum=0;  for(i=0; i<=3; ++i) for(j=0; j<=1;++j) {PII P=Make_pair (NODE[I][J].X,NODE[I][J].Y); if(! M[P]) + +num; M[P]=1; }            if(num!=4) {printf ("no\n");Continue;}///the number of vertices is not 4,no             for(i=0;i<4;++i) {                if(node[i][0].x==node[i][1].x) {///slope does not existk[i]=inf; Continue; }                Else if(node[i][0].y==node[i][1].y) {K[i]=0; Continue; }                Else{K[i]=(Double) (node[i][1].y-node[i][0].Y)/(Double) (node[i][1].x-node[i][0].x); }} sort (K,k+4); if(Fabs (k[0]-k[1]) <1e-5&&fabs (k[2]-k[3]) <1e-5){                if(Fabs (k[1]-k[2]) <1e-5) printf ("no\n"); Else{                    if(Fabs (k[1]*k[2]+1) <1e-5) printf ("yes\n"); Else if(Fabs (k[0]) <1e-5&&fabs (k[3]-inf) <1e-5) printf ("yes\n"); Elseprintf"no\n"); }            }            Elseprintf"no\n"); }    }    return 0;}

Hihocoder 1040 (Rectangle judging)