ZASHTO NE RABOTISH VO C++>???

#include<iostream>
#include<math.h>
using namespace std;
typedef struct point2D {
    double x;
    double y;
}
point2D;

float distance2D ( point2D t1, point2D t2) {
    return sqrt((t1.x-t2.x)*(t1.x-t2.x)+(t1.y-t2.y)*(t1.y-t2.y));
}

typedef struct point3D {
    double x;
    double y;
    double z;

}
point3D;

float distance3D (point3D t1, point3D t2) {

    return sqrt ((t1.x-t2.x)*(t1.x-t2.x)+(t1.y-t2.y)*(t1.y-t2.y)+(t1.z-t2.z)*(t1.z-t2.z));

}

int is_collinear(point2D t1, point2D t2, point2D t3) {
    if((t2.y-t1.y)/(t2.x-t1.x)==(t3.y-t2.y)/(t3.x-t2.x))
        return 1;
    else
        return 0;

}

int main () {
    float x1, y1, x2, y2;

    cin>>x1,y1;

    cin>>x2,y2;

    point2D t1 = {x1, y1};
    point2D t2 = {x2, y2} ;

    cout<<distance2D(t1,t2)<<'\n';

    float z1, z2;

    cin>>z1,z2;

    point3D t3 = {x1,y1,z1};
    point3D t4 = {x2,y2,z2};

    cout<<distance3D(t3,t4)<<'\n';

    point2D t5= {z1,z2};

    cout<<is_collinear(t1,t2,t5);

    return 0;
}