CF做题记录

Posted 2020-10-16

12/3

CF895B 二分

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 
 4 const int N=1e5+10;
 5 typedef long long LL;
 6 LL a[N];
 7 
 8 int main(){
 9     ios::sync_with_stdio(false);
10     LL n,x,k,ans=0;
11     cin>>n>>x>>k;
12     for(int i=0;i<n;i++) cin>>a[i];
13     sort(a,a+n);
14     for(int i=0;i<n;i++){
15         LL tmp=(LL)(ceil(1.0*a[i]/x)*x);
16         ans+=lower_bound(a,a+n,tmp+k*x)-lower_bound(a,a+n,max(a[i],(k-1)*x+tmp));
17     }
18     cout<<ans<<endl;
19     return 0;
20 }

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