c语言点在三角形内部的线段是,C语言判断点是否在三角形内或外#include#includestruct point{double x;double...

共回答了15个问题采纳率：93.3%

#include

#include

struct point

{

double x;

double y;

};

int area(float m,float n,float t)

{

float p,S;

p=(m+n+t)/2;

S=sqrt(p*(p-m)*(p-n)*(p-t));

return S;

}

void main()

{

struct point a,b,c,d,p;

float AB,BC,AC;

float S0,S1,S2,S3;

float DA,DB,DC;

scanf("%lf,%lfn",&a.x,&a.y);

scanf("%lf,%lfn",&b.x,&b.y);

scanf("%lf,%lfn",&c.x,&c.y);

AB=sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));

BC=sqrt((b.x-c.x)*(b.x-c.x)+(b.y-c.y)*(b.y-c.y));

AC=sqrt((a.x-c.x)*(a.x-c.x)+(a.y-c.y)*(a.y-c.y));

if((AB+BC)>AC && (AB+AC)>BC && (AC+BC)>AB){

printf("请输入D点坐标:n");

scanf("%lf,%lfn",&d.x,&d.y);

DA=sqrt((d.x-a.x)*(d.x-a.x)+(d.y-a.y)+(d.y-a.y));

DB=sqrt((d.x-b.x)*(d.x-b.x)+(d.y-b.y)+(d.y-b.y));

DC=sqrt((d.x-c.x)*(d.x-c.x)+(d.y-c.y)+(d.y-c.y));

S0=area(AB,BC,AC);

S1=area(DA,DB,AB);

S2=area(DA,DC,AC);

S3=area(DB,DC,BC);

if(S1+S2+S3-S0==0)

printf("点D位于三角形内部n");

else

printf("点D位于三角形外部n");

}

else

printf("不能构成三角形!");

}

//看看这样可比可以.你这个题还有更简单的方法,试试把每个边当成直线段,然后用d点带入和0比较大小,就会很简单.

1年前

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