View Code of Problem 67

#include<stdio.h>
int main(){
	int x1,y1,x2,y2,x3,y3,x4,y4;
	while(scanf("%d %d %d %d",&x1,&y1,&x2,&y2)!=EOF){
		scanf("%d %d %d %d",&x3,&y3,&x4,&y4);
		if(x1==x2&&x3==x4){
			if(x1==x3){
				printf("Yes\n");
			}
			else
				printf("No\n");
		}
		else if(x1 != x2&&x3!=x4){
			
			double k1,k2;
			k1 = (y2-y1)*1.0/(x2-x1);
			k2 = (y4-y3)*1.0/(x4-x3);
			if(k1 != k2){
				printf("Yes\n");
			}
			else{
				if((y1-k1*x1)==(y3-k2*x3)){
					printf("Yes\n");
				}
				else{
					printf("No\n");
				}
			}
			 
		}
		else{
			printf("Yes\n");
		}
	
	
	
 
	}
}