POJ 1269
中学的 又用上了。
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 #include <iostream> 2 #include <cstring> 3 #include <cstdio> 4 5 using namespace std; 6 7 int x1,y1,x2,y2,x3,y3,x4,y4; 8 double k1,k2,k3,d1,d2; 9 double x,y; 10 11 bool asure(){ 12 if(x1==x2||x3==x4){ 13 if(x1==x2&&x3==x4&&x1==x3) 14 printf("LINE\n"); 15 else if(x1==x2&&x3==x4&&x1!=x3) 16 printf("NONE\n"); 17 else{ 18 if(x1==x2){ 19 k2=(y3-y4)*1.0/(x3-x4)*1.0; 20 d2=y3*1.0-k2*x3; 21 x=x1; 22 y=k2*x+d2; 23 } 24 else { 25 k1=(y1-y2)*1.0/(x1-x2)*1.0; 26 d1=y1*1.0-k1*x1; 27 x=x3; 28 y=k1*x+d1; 29 } 30 printf("POINT %0.2lf %0.2lf\n",x,y); 31 } 32 return true; 33 } 34 return false; 35 } 36 37 38 int main(){ 39 int T; 40 while(scanf("%d",&T)!=EOF){ 41 printf("INTERSECTING LINES OUTPUT\n"); 42 while(T--){ 43 scanf("%d%d%d%d%d%d%d%d",&x1,&y1,&x2,&y2,&x3,&y3,&x4,&y4); 44 if(asure()) continue; 45 k1=(y1-y2)*1.0/(x1-x2)*1.0; k2=(y3-y4)*1.0/(x3-x4)*1.0; 46 if(k1==k2){ 47 k3=(y2-y3)*1.0/(x2-x3)*1.0; 48 if(k1==k3){ 49 printf("LINE\n"); 50 } 51 else printf("NONE\n"); 52 continue; 53 } 54 else { 55 d1=y1*1.0-k1*x1; 56 d2=y3*1.0-k2*x3; 57 y=(k2*d1-k1*d2)/(k2-k1); 58 x=(y-d1)*1.0/k1; 59 printf("POINT %0.2lf %0.2lf\n",x,y); 60 } 61 } 62 printf("END OF OUTPUT\n"); 63 } 64 return 0; 65 }