View Code of Problem 67

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