80 lines
1.5 KiB
C++
80 lines
1.5 KiB
C++
#include <cstdio>
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#include <cstring>
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#include <cmath>
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#include <queue>
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#include <iostream>
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#include <algorithm>
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using namespace std;
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#define lowbit(x) (x&(-x))
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const int maxn=5e4+10;
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struct node{
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double a,b;
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int num;
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}e[maxn];
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double l,r;
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int c[maxn];
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int cmp1(node x,node y)
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{
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if(x.a==y.a)return x.b<y.b;
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return x.a<y.a;
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}
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int cmp2(node x,node y)
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{
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if(x.b==y.b)return x.a>y.a;
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return x.b>y.b;
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}
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void add(int x,int val)
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{
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while(x<maxn)
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{
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c[x]+=val;
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x+=lowbit(x);
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}
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}
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int sum(int x)
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{
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int s=0;
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while(x>0)
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{
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s+=c[x];
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x-=lowbit(x);
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}
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return s;
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}
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int main()
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{
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int n;
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while(scanf("%d",&n)!=EOF)
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{
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int t,tt,i,j,ans=0;
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double x1,y1,x2,y2,k,b;
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t=tt=0;
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scanf("%lf%lf",&l,&r);
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for(i=0;i<n;i++)
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{
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scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);
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if(x1==x2)
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{
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if(x1<r&&x1>l)tt++;
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continue;
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}
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k=(y2-y1)/(x2-x1);
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b=y1-k*x1;
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e[t].a=l*k+b;
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e[t++].b=r*k+b;
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}
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sort(e,e+t,cmp1);
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for(i=0;i<t;i++)
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e[i].num=i+1;
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sort(e,e+t,cmp2);
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memset(c,0,sizeof(c));
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for(i=0;i<t;i++)
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{
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add(e[i].num,1);
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ans+=sum(e[i].num-1);
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}
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printf("%d\n",ans+tt*t);
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}
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return 0;
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}
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