bzoj1610 / P2665 [USACO08FEB]连线游戏Game of Lines

P2665 [USACO08FEB]连线游戏Game of Lines

第一次写快读没判负数....(捂脸)

暴力$O(n^2)$求斜率,排序判重。

注意垂直方向的直线要特判。

end.

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 #include<cctype>
 6 #define re register
 7 using namespace std;
 8 typedef double db;
 9 void read(int &x){
10     char c=getchar();x=0; bool f=1;
11     while(!isdigit(c)) f=(f&&c!='-'),c=getchar();
12     while(isdigit(c)) x=(x<<3)+(x<<1)+(c^48),c=getchar();
13     x=f?x:-x;
14 }
15 #define N 202
16 const db eps=1e-8;
17 struct node{int x,y;}a[N];
18 int n,tp,ans=1; db k[N*N];
19 int main(){
20     read(n);
21     for(re int i=1;i<=n;++i){
22         read(a[i].x);read(a[i].y);
23         for(re int j=1;j<i;++j){
24             db r1=a[i].y-a[j].y;
25             db r2=a[i].x-a[j].x;
26             if(r2<eps&&r2>-eps) k[++tp]=100000;//特判
27             else k[++tp]=r1/r2;
28         }
29     }sort(k+1,k+tp+1);
30     for(re int i=2;i<=tp;++i)
31         if(k[i]>k[i-1]) ++ans;//判重
32     printf("%d",ans);
33     return 0;
34 }
View Code

 

posted @ 2018-10-26 16:59  kafuuchino  阅读(90)  评论(0编辑  收藏  举报