View Code of Problem 67

#include<math.h>
int main()
{
	float x1, x2, x3, x4, y1, y2, y3, y4, k1, k2, b1, b2;
	while(scanf("%f %f %f %f %f %f %f %f", &x1, &y1, &x2, &y2, &x3, &y3, &x4, &y4)!=EOF)
	{
		if(x1 == x2 && x3 == x4)
		{
			if(x1 == x3)
				printf("Yes\n");
			else
				printf("No\n");
		}
		else
		{
		k1 = (y1 - y2) / (x1 - x2);
		k2 = (y3 - y4) / (x3 - x4);
		b1 = y1 - k1 * x1;
		b2 = y3 -k2 * x3;
		if(k1 == k2 && b1 != b2)
			printf("No\n");
		else
			printf("Yes\n");
		}
	}
}
/*
Main.c: In function 'main':
Main.c:5:2: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
  while(scanf("%f %f %f %f %f %f %f %f", &x1, &y1, &x2, &y2, &x3, &y3, &x4, &y4)!=EOF)
  ^
Main.c:5:8: warning: incompatible implicit declaration of built-in function 'scanf'
  while(scanf("%f %f %f %f %f %f %f %f", &x1, &y1, &x2, &y2, &x3, &y3, &x4, &y4)!=EOF)
        ^
Main.c:5:82: error: 'EOF' undeclared (first use in this function)
  while(scanf("%f %f %f %f %f %f %f %f", &x1, &y1, &x2, &y2, &x3, &y3, &x4, &y4)!=EOF)
                                                                                  ^
Main.c:5:82: note: each undeclared identifier is reported only once for each function it appears in
Main.c:10:5: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
     printf("Yes\n");
     ^
Main.c:10:5: warning: incompatible implicit declaration of built-in function 'printf'
Main.c:12:5: warning: incompatible implicit declaration of built-in function 'printf'
     printf("No\n");
     ^
Main.c:21:4: warning: incompatible implicit declaration of built-in function 'printf'
    printf("No\n");
    ^
Main.c:23:4: warning: incompatible implicit declaration of built-in function 'printf'
    printf("Yes\n");
    ^
*/