CHAP 2[C]j Checking if three coordinates form a straight line

Given three points (x1, y1), (x2, y2) and (x3, y3), write a program to check if all the three points fall on one straight line.

void main()
{
float x1,x2,x3,y1,y2,y3;
printf("\nEnter the three coordinates (x1,y1),(x2,y2),(x3,y3)");
scanf("%f%f%f%f%f%f",&x1,&y1,&x2,&y2,&x3,&y3);
if ((y2-y1)/(x2-x1)==(y3-y2)/(x3-x2))
printf("\nThe three points fall on the same line");
else
printf("\nThe three points are not collinear");
}